Google PageRank: What Do We Know About It?

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Everybody is using it, but (almost) nobody really knows how it works. Google PageRank is probably one of the most important algorithms ever developed for the Web. With billions of existing pages and millions of pages generated every day, the search issue in the Web is more complex than you probably think it is. PageRank, only one of hundreds of factors used by Google to determine best search results, helps to keep our search clean and efficient. But how is it actually done? How does Google PageRank work, which factors do have an impact on it and which don’t? And what do we really know about PageRank?

In this article we put the facts straight.

Over the last weeks we’ve done an extensive research and selected dozens of facts and suggestions about PageRank, which seem to be true in practice. Besides, we’ve collected academic papers related to the issue – such as scientific proposals for better search results (such as Topic-Sensitive PageRank); you’ll also find references to mathematical background of PageRank as well as 16 useful PageRank tools you can use to analyze und track the ranking of your web-projects.

Update: we’d like to apologize for some misleading facts we’ve initially included in this article. We’ve re-checked the sources and inaccurate or incomplete data. The .pdf-file won’t contain any mistakes. Thanks to all the readers who’ve pointed us to the mistakes (particularly Dan Grossman and Reuben Yau191).

  • Update: We are going to publish the .pdf-version of this post soon, so subscribe to our RSS-feed2 to keep track on our next posts.
  • You don’t have to read the whole article. Most important facts are selected in the beginning of the post as a brief summary.
  • You might be interested in reading our article Google AdSense: Facts, FAQs and Tools3, which should provide you with the most important facts, tools and resources about Google AdSense.
  • Update (28.07.2007): Spanish version4 of this article is available (thanks, Juan Manuel Lemus).

Google PageRank

Summary: How Does PageRank Work?

  1. PageRank is only one of numerous methods Google uses to determine a page’s relevance or importance.
  2. Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks not only at the sheer volume of votes; among 100 other aspects it also analyzes the page that casts the vote. However, these aspects don’t count, when PageRank is calculated.
  3. PageRank is based on incoming links, but not just on the number of them – relevance and quality are important (in terms of the PageRank of sites, which link to a given site).
  4. PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn)). That’s the equation that calculates a page’s PageRank.
  5. Not all links weight the same when it comes to PR.
  6. If you had a web page with a PR8 and had 1 link on it, the site linked to would get a fair amount of PR value. But, if you had 100 links on that page, each individual link would only get a fraction of the value.
  7. Bad incoming links don’t have impact on Page Rank.
  8. Ranking popularity considers site age, backlink relevancy and backlink duration. PageRank doesn’t.
  9. Content is not taken into account when PageRank is calculated.
  10. PageRank does not rank web sites as a whole, but is determined for each page individually.
  11. Each inbound link is important to the overall total. Except banned sites, which don’t count.
  12. PageRank values don’t range from 0 to 10. PageRank is a floating-point number.
  13. Each Page Rank level is progressively harder to reach. PageRank is believed to be calculated on a logarithmic scale.
  14. Google calculates pages PRs permanently, but we see the update once every few months (Google Toolbar).

Summary: Impact on Google PageRank

  1. Frequent content updates don’t improve Page Rank automatically. Content is not part of the PR calculation.
  2. High Page Rank doesn’t mean high search ranking.
  3. DMOZ and Yahoo! Listings don’t improve Page Rank automatically.
  4. .edu and .gov-sites don’t improve Page Rank automatically.
  5. Sub-directories don’t necessarily have a lower Page Rank than root-directories.
  6. Wikipedia links don’t improve PageRank automatically (update: but pages which extract information from Wikipedia might improve PageRank).
  7. Links marked with nofollow-attribute don’t contribute to Google PageRank.
  8. Efficient internal onsite linking has an impact on PageRank.
  9. Related high ranked web-sites count stronger. But: “a page with high PageRank may actually pass you less if it has more links, because it’s spread too thin.” [RY5]
  10. Links from and to high quality related sites have an impact on Page Rank.
  11. Multiple votes to one link from the same page cost as much as a single vote.

1.1. What is PageRank?

  • “PageRank is [only] one of the methods Google uses to determine a page’s relevance or importance.” [PageRank Explained Correctly6]
  • “Google uses many factors in ranking. Of these, the PageRank algorithm might be the best known. PageRank evaluates two things: how many links there are to a web page from other pages, and the quality of the linking sites. With PageRank, five or six high-quality links from websites such as www.cnn.com and www.nytimes.com would be valued much more highly than twice as many links from less reputable or established sites.” [Google Librarian Central257]
  • “PageRank has only ever been an approximation of the quality of a web page and has never had anything to do with the measuring of the topical relevance of a web page. Topical relevance is measured with link context and on-page factors such as keyword density, title tag, and everything else.” [PageRank: An Essay8]

1.2. How Does PageRank work?

  • No one really knows.“No one knows for sure how PageRank is currently calculated by Google.” [Google PageRank Explained]
  • PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn)). “That’s the equation that calculates a page’s PageRank. In the equation ‘t1 – tn’ are pages linking to page A, ‘C’ is the number of outbound links that a page has and ‘d’ is a damping factor, usually set to 0.85.”
  • We can think of it in a simpler way: a page’s PageRank = 0.15 + 0.85 * (a “share” of the PageRank of every page that links to it). “share” = the linking page’s PageRank divided by the number of outbound links on the page. A page “votes” an amount of PageRank onto each page that it links to. The amount of PageRank that it has to vote with is a little less than its own PageRank value (its own value * 0.85). This value is shared equally between all the pages that it links to.” [Google’s Page Rank119]
  • “The core Google PageRank algorithm “distributes” it’s established PR across all of the outbound links. Put differently, if you had a web page with a PR8 and had 1 link on it, the site linked to would get a fair amount of PR value. But, if you had 100 links on that page, each individual link would only get a fraction of the value.” [The Importance of PageRank10]
  • “From this, we could conclude that a link from a page with PR4 and 5 outbound links is worth more than a link from a page with PR8 and 100 outbound links. The PageRank of a page that links to yours is important but the number of links on that page is also important. The more links there are on a page, the less PageRank value your page will receive from it.” [Google’s Page Rank119]
  • “PageRank [..] uses the link structure as an indicator of an individual page’s value. Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks at considerably more than the sheer volume of votes, or links a page receives; e.g. it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.” [Google: Technology12]
  • Not all links weight the same when it comes to PR. So an ‘important’ page linking to you gives you more PR than a ‘less important’ one. […] A factor in PR propagation is the number of out-links the ‘voting’ page have. So a PR4 page with only one out-link on it might give you more weight than a PR5 page with 100 out-links on it. A typical example here would be the famous milliondollarhomepage. This page is PR7 page with hunderds of out-links therefore its weight is would contribute very little to your page PR.” [Google PageRank Explained]
  • Each Page Rank level is progressively harder to reach. “PageRank is logarithmic in its calculation. In the same way that the earthquake Richter scale is exponential in calculation, so too is the mathematics behind Google PageRank. It takes one step to move from a PR0 to a PR1, it takes a few more steps to PR3, it takes even more steps to PR4, and many more steps again to PR5, and so one.” [Google Page Rank FAQ13]

Google PageRank Explained14
[via einfach-persoehnlich15]

  • “PageRank does not rank web sites as a whole, but is determined for each page individually. Further, the PageRank of page A is recursively defined by the PageRanks of those pages which link to page A.” [The Page Rank algorithm16]
  • “Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to user’s search. Google examines all aspects of the page’s content (and the content of the pages linking to it) to determine if it’s a good match for user’s queries.” [What Is Google PageRank?54534017]
  • “Google calculates pages PRs once every few months (PR update). After a PR update is done, all pages are assigned a new PR by Google and you will have this PR until a new PR update is done. New sites that were just launched will have a PR of 0 until an update is done by Google so that they are assigned an appropriate PR.” [Google PageRank Explained]
  • “Google PageRank is calculated all the time, but what we see in the Google Toolbar 18 (or other online PR tools) is a snapshot in time which is updated every 3 months or so.” [Reuben Yau191]
  • PageRank values don’t range from 0 to 10. PageRank is a floating-point number. “It’s more accurate to think of it as a floating-point number. Certainly our internal PageRank computations have many more degrees of resolution than the 0-10 values shown in the toolbar.” [Matt Cutts20]
  • “We’re sure that their curve is similar to an exponential curve with each new “plateau” being harder to reach than the last. I have personally done some research into this21, and so far the results point to an exponential base of 4. So a PR of 6 is 4 times as difficult to attain as a PR of 5. [..] The difference between a high PR of 6, and a low PR of 6, could be hundreds or thousands of links.” [Top 10 Google Myths Revealed362422]
  • “PageRank is believed to be calculated on a logarithmic scale. What this roughly means is that the difference between PR4 and PR5 is likely 5-10 times than the difference between PR3 and PR4. So, there are likely over a 100 times as many web pages with a PageRank of 2 than there are with a PageRank of 4. This means that if you get to a PageRank of 6 or so, you’re likely well into the top 0.1% of all websites out there. If most of your peer group is straggling around with a PR2 or PR3, you’re way ahead of the game.” [Importance of Google PageRank23]
  • “The fact is that PageRank is based on incoming links, but not just on the number of them. Instead PageRank is based on the value of your incoming links. To find the value of an incoming link look at the PR of the source page, and divide it by the number of links on that page. It’s very possible to get a PR of 6 or 7 from only a handful of incoming links if your links are “weighty” enough.” [Top 10 Google Myths Revealed362422]
  • Google tries to find pages that are both reputable and relevant. If two pages appear to have roughly the same amount of information matching a given query, we’ll usually try to pick the page that more trusted websites have chosen to link to. Still, we’ll often elevate a page with fewer links or lower PageRank if other signals suggest that the page is more relevant. For example, a web page dedicated entirely to the civil war is often more useful than an article that mentions the civil war in passing, even if the article is part of a reputable site such as Time.com.” [Google Librarian Central257]
  • Links don’t give PR away, they are votes. “When a page votes its PageRank value to other pages, its own PageRank is not reduced by the value that it is voting. The page doing the voting doesn’t give away its PageRank and end up with nothing. It isn’t a transfer of PageRank. It is simply a vote according to the page’s PageRank value.” [Page Rank Explained26]
  • “We know from the paper “The Anatomy of a Large-Scale Hypertextual Web Search Engine” (Paper) that the PageRank of a Web page is a number calculated using a recursive algorithm in which the page receives a share of the PageRank of each page that links to it.” [Google PageRank3927]
  • Crawlers don’t analyze web-sites permanently. “It often takes two full monthly updates for all of your incoming links to be discovered, counted, calculated and displayed as backlinks.” [Google FAQ28]

1.3. Which factors do have an impact on PageRank?

  • Each inbound link is important to the overall total. Except banned sites. “PageRank is a form of a voting system. A link to a page is a vote for that page. Higher PageRank pages are viewed by Google as more important. Their votes are given more value by Google — much more value, in some cases. In general, the more voting links, the stronger the PageRank.” [Google PageRank FAQ29]
  • Adding new pages can decrease Page Rank. “The effect is that, whilst the total PageRank in the site is increased, one or more of the existing pages will suffer a PageRank loss due to the new page making gains. Up to a point, the more new pages that are added, the greater is the loss to the existing pages. With large sites, this effect is unlikely to be noticed but, with smaller ones, it probably would.” [PageRank Explained4830]
  • Page Rank can decrease. “You can lose some important links that are no longer linking to your site. PR loss can also occur if some of your linking partners also experience a drop in their own PR, possibly setting off a chain reaction of lower PageRank all through the immediate linking network.” [Google PageRank FAQ31]
  • Links from and to high quality related sites are important. “The more closely related the pages, the higher the PageRank amount transferred.” “Linking to high quality sites shows the search engines your site is very useful to your visitors. Unless your site has been around for years and is well established and trusted by Google, this factor will have an adverse effect on your site’s overall ranking. Linking only to high quality content sites will give your site an edge over your competition.” [Let Google’s Algorithm Show You The Traffic525032, FAQ33]
  • Incoming Links from popular sites are important. If pages linking to you have a high PageRank then your page gains some part of their reputation.
  • Site can be banned if it links to banned sites. “Be extremely careful of any out-going links from your site. Don’t link to bad neighborhoods (link farms, banned sites, etc.) Google will penalize you for bad links so always check the PageRank of the sites you’re linking to from your site.” [SiteProNews34]
  • Illegal activities will penalize your PageRank and possibly ban your site from Google. “Hidden text, deceptive redirects, cloaking, automated link exchanges, or anything else against Google’s quality guidelines35” can ban your site from Google.
  • Myth: the higher your google PageRank, the better the results. “While pages with a higher PageRank do tend to rank better, it is perfectly normal for a site to appear higher in the results listings even though it has a lower PageRank than competing pages. [..] Google examines the context of your incoming links, and only those links that relate to the specific keyword being searched on will help you achieve a higher ranking for that keyword.” [Top 10 Google Myths Revealed362422]
  • Related high ranked web-sites count stronger (or don’t they?). “One-way inbound links from websites with topics that are related to your website’s topic will help you gain a higher Page Rank.” Other one-way inbound links from pages with high page rank but unrelated topics do help a little, but not nearly as much. [What Is Page Rank?3837]
  • Different pages from a site can have different Page Rank. “Search engines crawl and index webpages not websites, that is why your page rank may vary from page to page within your website.” [What Is Page Rank?3837]

1.4. Which factors don’t have an impact on PageRank?

  • Frequent content updates don’t improve PR automatically.” Although Google might send crawlers more frequently to analyze your site, what is more significant are links pointing to you.
  • “Content is not taken into account when PageRank is calculated. Content is taken into account when you actually perform a search for specific search terms.” [Google PageRank3927]
  • “High PageRank does NOT guarantee a high search ranking for any particular term. If it did, then PR10 sites like Adobe would always show up for any search you do. They don’t.” [What Is Google PageRank?54534017
  • Google considers site age, backlink relevancy and backlink duration. PageRank doesn’t. If backlink isn’t relevant, it won’t weight much.
  • Wikipedia Links don’t improve Page Rank. “Wikipedia implemented a no-follow rule, indicating that outbound links should not be followed by search engine spiders.” [A Survival Guide to SEO & Wikipedia41]
  • Listing in DMOZ and Yahoo! doesn’t give your site a special PR Bonus. “Google uses Open Directory Project (DMOZ.org), to power its directory. Coupling that fact with the observation that sites listed in DMOZ often get decent and inexplicable PageRank boosts, has lead many to conclude that Google gives a special bonus to sites listed in DMOZ. This is simply not true. The only bonus gained from being in DMOZ is the same bonus a site would achieve from being linked to by any other site.” However, DMOZ data is used by hundreds of sites.” [Top 10 Google Myths Revealed42]
  • Sub-directories don’t necessarily have a lower Page Rank than root-directories. Depending on the popularity of a web-site your subdirectories can have a higher PageRank than the root pages.
  • Meta-Tags don’t improve PageRank. “Google can sometimes use the meta description tag to create an abstract for your site, so it may be useful to you if your home page is primarily composed of graphics. However, do not expect it to increase your rank.” [10 Google Myths Revealed43]
  • .edu and .gov-sites do not provide higher PageRank (or do they?).“We don’t really have much in the way to say “Oh this is a link from the ODP, or .gov, or .edu, so give that some sort of special boost.” Its just those sites tend to have higher PageRank because-because more people link to them and reputable people link to them.” [A Google Myth Busted44]

No Follow Treatment45

  • Links marked with nofollow-attribute don’t contribute to Google PageRank. “Google implemented a new value, “nofollow”, for the rel attribute of HTML link and anchor elements, so that website builders and bloggers can make links that Google will not consider for the purposes of PageRank — they are links that no longer constitute a “vote” in the PageRank system.” [Wikipedia: PageRank6246]
  • Multiple votes to one link from the same page cost as much as a single vote. “It is reasonable to assume that a page can cast only one vote for another page, and that additional votes for the same page are not counted.” [PageRank FAQ47]
  • Links from one page to itself don’t improve Page Rank. “It is reasonable to assume that a page can’t vote for itself, and that such links are not counted.” [PageRank Explained4830]
  • Bad incoming links don’t have impact on Page Rank. “Where the links come from doesn’t matter. Sites are not penalized because of where the links come from.” [Google PageRank49]
  • Dangling links don’t have impact on Page Rank. “Dangling links are simply links that point to any page with no outgoing links. They affect the model because it is not clear where their weight should be distributed, and there are a large number of them. Because dangling links do not affect the ranking of any other page directly, we simply remove them from the system until all the PageRanks are calculated. After all the PageRanks are calculated they can be added back in without affecting things significantly.” [PageRank Paper]

1.5. Ranking Factors (related to PageRank)

  • Efficient internal onsite linking is important. “Internal linking is important to your overall ranking. Make sure your linking structure is easy for the spiders to crawl. Most suggest a simple hierarchy with links no more than three clicks away from your home/index page. Creating traffic modes or clusters of related links within a section on your site has proven very effective.” [Let Google’s Algorithm Show You The Traffic525032
  • Anchor text is important. The more specific is the reference, the better Google can evaluate it and consider it in relates search queries.
  • Google penalizes link farms. “Google is only concerned with pages of over 100 outgoing links. Google considers overly linked pages to be link farms, and they are penalized as such.” [Google FAQ51]
  • Headers (h1, … ,h6), strong tags and semantic content are important. (Update: But it doesn’t improve PageRank.) “Place it in the description and meta tags, place it in bold/strong tags, but keep your content readable and useful. Be aware of the text surrounding your keywords, search engines will become more semantic in the coming years so context is important.” [Let Google’s Algorithm Show You The Traffic525032
  • “The anchor text of a link is often far more important than whether it’s on a high PageRank page.” [What Is Google PageRank?54534017
  • “If you really want to know what are the most important, relevant pages to get links from, forget PageRank. Think search rank. Search for the words you’d like to rank for. See what pages come up tops in Google. Those are the most important and relevant pages you want to seek links from. That’s because Google is explicitly telling you that on the topic you searched for, these are the best.” [What Is Google PageRank?54534017]

2.1. Google PageRank: Theory & Scientific Background

  • A Survey of Google’s PageRank55
    Calculation of Page Rank, Page Rank Implementation, Inbound Links, Outbound Links, Number of Pages, PageRank Distribution, Additional Factors and more.
  • The Lineal Algebra Behind Google56
    The $25,000,000,000 Eigenvector – The Linear Algebra Behind Google. Google’s success derives in large part from its PageRank algorithm, which ranks the importance of webpages according to an eigenvector of a weighted link matrix. Analysis of the PageRank formula provides a wonderful applied topic for a linear algebra course.
  • The Intelligent Surfer: Probabilistic Combination of Link and Content Information in PageRank57
    We propose to improve Page-Rank by using a more intelligent surfer, one that is guided by a probabilistic model of the relevance of a page to a query. Efficient execution of our algorithm at query time is made possible by precomputing at crawl time (and thus once for all queries) the necessary terms.
  • Topic-Sensitive PageRank58
    To yield more accurate search results, we propose computing a set of PageRank vectors, biased using a set of representative topics, to capture more accurately the notion of importance with respect to a particular topic. By using these (precomputed) biased PageRank vectors to generate query-specific importance scores for pages at query time, we show that we can generate more accurate rankings than with a single, generic PageRank vector.
  • Method for node ranking in a linked database59
    A method assigns importance ranks to nodes in a linked database, such as any database of documents containing citations, the world wide web or any other hypermedia database. The rank assigned to a document is calculated from the ranks of documents citing it. In addition, the rank of a document is calculated from a constant representing the probability that a browser through the database will randomly jump to the document. By Page and Lawrence.
  • How Google Finds Your Needle in the Web’s Haystack60
    Mathematical Background of Google PageRank. By David Austin, Grand Valley State University
  • A Large-Scale Hypertextual Web Search Engine61
    Original Slides, by Larry Page.
  • Wikipedia: PageRank6246
    Mathematical Theory Behind Google PageRank

3.1. Google PageRank Tools & Services

  • PageRank Search63
    Showing search results in order of PageRank.
  • Google PageRank Inspector64.
    Google PageRank inspector is PHP scripts that can seek all of your website, include out linked page or not, and display Pagerank value for each of your website pages. New pages linked by high pagerank pages can be indexed in google quickly and have higher keyword rank in google search.
  • Google’s PageRank – Calculator65
    The results produced by the calculator indicate each page’s PageRank share and are not equivalent to the values in the Google toolbar.

PageRank Calculator66

  • Webmastereyes67, Visual PageRank View68
    The results will show the page given along with the PageRank of each link on that page. You also have the option to show “nofollow” and external links.
  • Smart PageRank69
    Checks PageRank from multiple datacenters and sends emails automatically if PageRank is updated.
  • Google PageRank Notifier70
    “This script will send you an email whenever the PageRank of the given page changes. PageRank is taken from the Google Toolbar “API” and is updated once an hour.”
  • Google PageRank™ Checker71 (registration required)
    You can monitor site’s PageRank via RSS and you can also be notified via e-mail when the PageRank has been changed.

PageRank Checker72

  • Dig PageRank73
    Checks the current Page Rank of a page in over 100 Google data centers.
  • Live PageRank Check74
    The Live PageRank value may be used as an indicator of what will show when Google decides to export the PageRank values to the Google Toolbar. The Live PageRank calculator gives you the current PageRank value in the Google index, not just the snapshot that is displayed in the toolbar. Google updates its internal PageRank value continuously as the web changes and their index is updated. Only once every third month or so this value is exported to be displayed in the Google Toolbar.
  • Page Rank Widget75 for Mac OS X.
    Llittle Widget finds the Google Page Rank for any URL by calculating the checksum and requesting the PR from Google’s servers.

PageRank Dashboard76

PageRank Decoder86

3.2. Google Tools & Services

Footnotes

  1. 1 http://www.reubenyau.com/smashing-magazine-google-pagerank-article-misleading/
  2. 2 http://www.smashingmagazine.com/wp-rss.php
  3. 3 http://www.smashingmagazine.com/2007/03/22/google-adsense-facts-faqs-and-tools/
  4. 4 http://dotpress.wordpress.com/2007/07/03/google-pagerank-que-necesitamos-conocer/
  5. 5 http://www.reubenyau.com/smashing-magazine-google-pagerank-article-misleading/
  6. 6 http://www.iprcom.com/papers/pagerank/
  7. 7 http://www.google.com/librariancenter/articles/0512_01.html
  8. 8 http://www.websitepublisher.net/blog/2006/11/17/pagerank-an-essay/
  9. 9 http://www.webworkshop.net/pagerank.html
  10. 10 http://www.smallbusinesshub.com/blog/tabid/6307/bid/45/The-Importance-of-Google-PageRank-A-Guide-For-Small-Business-Executives.aspx
  11. 11 http://www.webworkshop.net/pagerank.html
  12. 12 http://www.google.com/technology/
  13. 13 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/1/
  14. 14 http://searchengineland.com/070508-152900.php
  15. 15 http://www.einfach-persoenlich.de/2007-05-18/google-der-google-pagerank-berg-anschaulich-visualisiert.html
  16. 16 http://pr.efactory.de/e-pagerank-algorithm.shtml
  17. 17 http://searchengineland.com/070426-011828.php
  18. 18 http://livepr.raketforskning.com/
  19. 19 http://www.reubenyau.com/smashing-magazine-google-pagerank-article-misleading/
  20. 20 http://www.mattcutts.com/blog/more-info-on-pagerank/
  21. 21 http://www.sitepointforums.com/showthread.php?s=&threadid=77168
  22. 22 http://www.sitepoint.com/article/top-10-google-myths-revealed
  23. 23 http://www.smallbusinesshub.com/blog/tabid/6307/bid/45/The-Importance-of-Google-PageRank-A-Guide-For-Small-Business-Executives.aspx
  24. 24 http://www.sitepoint.com/article/top-10-google-myths-revealed
  25. 25 http://www.google.com/librariancenter/articles/0512_01.html
  26. 26 http://www.webworkshop.net/pagerank.html
  27. 27 http://www.sitepoint.com/article/democracy-corporate-muscle
  28. 28 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/2/
  29. 29 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/
  30. 30 http://www.webworkshop.net/pagerank.html
  31. 31 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/4/
  32. 32 http://www.sitepronews.com/archives/2007/apr/18.html
  33. 33 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/1/
  34. 34 http://www.sitepronews.com/archives/2006/may/22.html
  35. 35 http://www.google.com/support/webmasters/bin/answer.py?answer=35769
  36. 36 http://www.sitepoint.com/article/top-10-google-myths-revealed
  37. 37 http://www.selfseo.com/story-18694.php
  38. 38 http://www.selfseo.com/story-18694.php
  39. 39 http://www.sitepoint.com/article/democracy-corporate-muscle
  40. 40 http://searchengineland.com/070426-011828.php
  41. 41 http://searchengineland.com/070508-061206.php
  42. 42 http://www.sitepoint.com/article/top-10-google-myths-revealed/2
  43. 43 http://www.sitepoint.com/article/top-10-google-myths-revealed/2
  44. 44 http://www.websitepublisher.net/blog/2006/08/03/a-google-myth-busted/
  45. 45 http://www.searchenginejournal.com/how-google-yahoo-askcom-treat-the-no-follow-link-attribute/4801/
  46. 46 http://en.wikipedia.org/wiki/PageRank
  47. 47 http://www.webworkshop.net/pagerank.html
  48. 48 http://www.webworkshop.net/pagerank.html
  49. 49 http://www.webworkshop.net/pagerank.html
  50. 50 http://www.sitepronews.com/archives/2007/apr/18.html
  51. 51 http://www.seochat.com/c/a/Google-Optimization-Help/Google-PageRank-Frequently-Asked-Questions/3/
  52. 52 http://www.sitepronews.com/archives/2007/apr/18.html
  53. 53 http://searchengineland.com/070426-011828.php
  54. 54 http://searchengineland.com/070426-011828.php
  55. 55 http://pr.efactory.de/
  56. 56 http://www.rose-hulman.edu/~bryan/googleFinalVersionFixed.pdf
  57. 57 http://www.cs.washington.edu/homes/pedrod/papers/nips01b.pdf
  58. 58 http://dbpubs.stanford.edu:8090/pub/2002-6
  59. 59 http://www.freepatentsonline.com/6285999.html
  60. 60 http://www.ams.org/featurecolumn/archive/pagerank.html
  61. 61 http://dbpubs.stanford.edu:8091/diglib/pub/slides/berkeleydlijan98/berkeleygoogle2/
  62. 62 http://en.wikipedia.org/wiki/PageRank
  63. 63 http://www.seochat.com/?tool=7&option=com_seotools&hl=en&lr=&ie=UTF-8&oe=UTF-8&q=&result_mode=pagerank&num=10&btnG=+++Search+++
  64. 64 http://www.rightscripts.com/pagerank/
  65. 65 http://www.webworkshop.net/pagerank_calculator.php
  66. 66 http://www.webworkshop.net/pagerank_calculator.php
  67. 67 http://www.webmastereyes.com/
  68. 68 http://www.iwebtool.com/visual_pagerank
  69. 69 http://www.smartpagerank.com/
  70. 70 http://pagerank.freddy.eu.org/
  71. 71 http://sitening.com/seo-tools/page-rank/my-checker/
  72. 72 http://sitening.com/seo-tools/page-rank/my-checker/
  73. 73 http://www.digpagerank.com
  74. 74 http://livepr.raketforskning.com/
  75. 75 http://aroussi.com/article/32/google-page-rank-widget
  76. 76 http://aroussi.com/article/32/google-page-rank-widget
  77. 77 http://www.iwebtool.com/pagerank_prediction
  78. 78 http://www.iwebtool.com/tools/
  79. 79 http://www.smartpagerank.com/pagerank-backlinks.php
  80. 80 http://seobench.com/pr-overlay/
  81. 81 http://phpmagazine.net/prmapper/
  82. 82 http://seobench.com/pr-overlay/proverlay.xpi
  83. 83 http://www.search-this.com/pagerank-decoder/
  84. 84 http://www.seroundtable.com/archives/002085.html
  85. 85 http://www.seroundtable.com/archives/002085.html
  86. 86 http://www.search-this.com/pagerank-decoder/
  87. 87 http://www.seocompany.ca/pagerank/page-rank-update-list.html
  88. 88 http://www.vaughns-1-pagers.com/internet/google-ranking-factors.htm
  89. 89 http://www.google.com/support/webmasters/bin/answer.py?answer=35769
  90. 90 https://www.google.com/webmasters/tools/siteoverview?hl=en
  91. 91 https://www.google.com/webmasters/tools/reinclusion?hl=en
  92. 92 http://dmoz.org/Computers/Internet/Searching/Search_Engines/Google/Tools/

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Vitaly Friedman loves beautiful content and doesn’t like to give in easily. Vitaly is writer, speaker, author and editor-in-chief of Smashing Magazine. He runs responsive Web design workshops, online workshops and loves solving complex performance problems in large companies. Get in touch.

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  1. 1

    Excellent article, very thorough

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  2. 52

    Am I the only person who gets the feeling that it is “pointless” even worrying about page rank? The page rank you see in G tool bar it seems is not up to date…..adding content does not immediately result in R change and the bombshell which many figured out months ago is that

    “page rank does not guarantee ranking = traffic”

    So Why bother?

    Rob

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  3. 103

    hmm, I think PR is already not important for most of developers, who are up to fresh market news.. Pagerank should be important only for google, now we should look at alexa ratings more, and to look for better keywords ant content, but pagerank isn’t giving big important for google search results..

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  4. 154

    Thank you, its a very impressive article. Fantastic work! I have been looking for an article like this.

    0
  5. 205

    A really good guide to pagerank, good job!!!

    0
  6. 256

    mark rushworth

    June 6, 2007 4:46 pm

    update for you wikipedia links are all rel nofollow as of a few months back.

    0
  7. 307

    Excellent work! This article could easily worth hundreds of dollar.

    0
  8. 358

    Phill Midwinter

    June 6, 2007 5:05 pm

    Lovely collation of plagiarism that passes for an article on an attribute that’s so outdated as to be practically useless. Rather than read this stuff, go and get yourselves a professional SEO company people.

    0
  9. 409

    What to say??? As always amazing article. I would like to know if important brands have a high PageRank for being important outside internet or for doing it the right way inside internet…
    ;-)

    0
  10. 460

    This is pure :3 and >:3

    It’s not like I really cared for pagerank, but now I do!

    0
  11. 511

    Very nice post, thanks for the useful information!

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  12. 562

    Great article!!!

    My blog have pr 3 i try to create another website without any link on the internet only one link on my front page, some time after the blank page have pr 2….
    i already do this with 3 diferent sites and all the same one link on my blog front page during a while and the other site get pr 2….

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  13. 613

    Great! Is it possible to publish a german version on http://www.seo-scene.de? Or do Dr. Web this job?

    0
  14. 664

    Greate article!

    0
  15. 715

    Nice article. Gave insight to PR.

    0
  16. 766

    Kenneth Blomster

    June 6, 2007 11:31 pm

    Excellent article. Thanks for this!

    0
  17. 817

    You guys always have such detailed and interesting articles. thumbs up

    0
  18. 868

    Very informative!

    0
  19. 919

    Great article!
    I would never like to know anything more than you have given here.
    I had few doubts and now it seems this article has cleared my doubts.
    keep up the great work guys!

    0
  20. 970

    Nice, really good… Thx.

    0
  21. 1021

    Mansoor Nathani

    June 7, 2007 4:34 pm

    Excellent explanation of Google Pagerank.

    Over 800 people have tagged this in del.icio.us as of June 7th only 2 days after this has been posted.

    0
  22. 1072

    Thank you guys for the great article. I´m deeply impressed.

    0
  23. 1123

    Good articles:)

    0
  24. 1174

    Wonderful! Every article that gets published on your site is helping me improve in some or the other way. Thanks a lot for yet another useful article. Looking forward to the PDF version.
    Cheers!!

    0
  25. 1225

    Excellent article! Thanks!!!

    For a long time I have been using http://www.websitegrader.com to track my website’s marketing effectiveness and it has been really useful. This article gives me additional detail on the nuances of Page Rank. Thanks.

    0
  26. 1276

    Great article, never seen such explanation to pagerank.
    btw digpagerank tool checks pr in 689 datacenters not 100. :-)

    0
  27. 1327

    “Links marked with nofollow-attribute don’t contribute to Google PageRank.”
    I have very strong reasons to believe this is not true. Hate to say this(I am sure spammers will go mad), but 2 years ago I had small site hosted on free hosting and free subdomain. I never did some link building for it, but I left comment on one page that got pr8 on next update and my site got pr7 from that link only. It was Worpdress comment and it had nofollow like all other WP blogs.
    So, I would say those links pass pr.

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  28. 1378

    Really amazing!!! How do you guys know all these?? :D

    0
  29. 1429

    Matt Ellsworth

    June 8, 2007 1:37 pm

    awesome blog post – i have learned so much about page rank here… more so than all of my other research.

    0
  30. 1480

    Jermayn Parker

    June 8, 2007 1:57 pm

    dizzy with all that info. Even if we only get half of that, it will be a better world :)

    0
  31. 1531

    Good extensive researched…

    0
  32. 1582

    Philippe MARTY

    June 8, 2007 8:17 pm

    Great work !
    I was searching for a while all that bunch of information.

    Many thanks for this useful job !

    0
  33. 1633

    Great article, especially like the pagerank mountain diagram. Is this article available as a pdf?

    0
  34. 1684

    Manny Hernandez

    June 9, 2007 5:21 am

    This is the most amazing compilation of knowledge that I’ve ever encountered on the topic of PageRank. Thanks for putting it together!

    0
  35. 1735

    Emanuel Felipe

    June 9, 2007 6:02 am

    Thanks for this great article…
    Can I translate it? (Smashing Magazine will recive the credits of course)

    0
  36. 1786

    Wonderful resource. I thought it was too good not to be shared so I have translated it into French for us non English-speaking froggies (it means a lot of people, even in the IT world). If you have a problem with copyright or whatever, let me know I’ll remove it immediately.

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  37. 1837

    I don’t doubt the importance of Google in general, but I have to pause to wonder if Google PageRant isn’t a little bit like Alexa ranking. That is, it seems like a self-propagating – almost viral – factor whose significance is largely predicated by the fact that bloggers & webmasters consider it to be significant.

    Or in other words, the primary factor in making those “only available for a limited time” Nascar plates (with the 24-karat gold rim) on cheesy late-night informercials “collectable” is that someone declared them to be so.

    Not bashing the Goog, just thinking out loud…

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  38. 1888

    This blog entry contains some useful info on PR. Thanks. -Geoff

    0
  39. 1939

    it doesnt say anything about changing web hosts. Does changing web hosts affect PR or google searching?

    0
  40. 1990

    daryoko rispurwanto

    June 10, 2007 11:55 pm

    Very informative article, thank you..

    0
  41. 2041

    Hmmm pretty interesting. I think most of us bloggers have little hope of getting a high rank ever : )

    0
  42. 2092

    Inspiring and Impressive.

    0
  43. 2143

    John Macpherson

    June 11, 2007 10:59 pm

    Unfortunately this article just increases the myth that PageRank is the be all and end all of SEO. Its just one factor of many. Do the top 10 sites on any search term rank with the highest PR at the top descending?… Nope.

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  44. 2194

    hej,

    I really appreciate your work and your research seems to be well done but I am missing some links to SEO-pages in your compilation that IMHO should not be left out because of their valued content. most notably “Google Search Engine Ranking Factors” by SEOmoz.

    and when it comes to pagerank calculation or to the number of inboud links necessary to gain a certain PR I do miss some tables like the one by Bob Wakfer”.

    if I missed those articles being mentioned somewhere I apologize; i did not find them or something similar.

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  45. 2245

    Excellent work, very detailed. Thanks. Looking forward to PDF.

    0
  46. 2296

    A great article!! thank you

    0
  47. 2347

    Phew .. that’s an amazing article. Good work guys.

    0
  48. 2398

    Great article thanks!

    0
  49. 2449

    Great explanation, thanks for the effort.

    0
  50. 2500

    Lydia's assistant

    June 15, 2007 11:23 pm

    I’m not convinced everything present here is true, in fact some it seems to conflict (i.e. PR no impact on search, high PR pages tend to rank on search) but still a very powerful collection of information. Thanks for the good read!

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