With advertising, a curious thing happens: most people want its benefits but are rarely willing to put up with its hassles. Those who run websites and applications have enough on their plates without having to worry about handling transactions, putting banners across their website or hearing requests from advertisers. Moreover, users have little to no interest in even looking at advertisements that flank a website's content, some going so far as to block ads before they're delivered. So, what's a website owner to do?
Advertising hasn't always been this way. Some people even enjoy them. Scary thought, I know, but stay with me. You know those previews shown before movies and those signs outside of gas stations announcing fuel prices? Those are rarely seen as advertisements at all. That's because people find them informative, helpful and engaging. Heck, some people say they watch the Superbowl for the advertisements themselves. So why are websites any different? What has changed online that people (apparently) find less acceptable than offline? Not much, really… well, not much unless you count that whole "Internet" thing.
As a general rule, when people surf the Web, they're in control of the experience. If someone wants information about a particular topic, they might query Google or look up an article on Wikipedia. Regardless of what they do, they choose how to obtain the information they want. The traditional advertising model — shout at your audience until it listens (as Groundswell would put it) — is diametrically opposed to this.