In a recent blog post, Phil Ringnalda took O'Reilly and Associates (publishers of the finest tech books in the world) to task for what he characterized as "search engine spam" in the advertising on O'Reilly's sites. Tim O'Reilly, the publisher and founder of ORA, has undertaken an investigation into this and has blogged a long piece about what he found:
# it's become clear to me on investigation that these folks are indeed paying us for our Google rank, and not just for clickthroughs. We just aren't targeted enough for their ads to be justified on a click-through basis. What's more, using Google's link: keyword to check for top links to these particular advertisers shows that the O'Reilly sites they advertise on are among their chief link sources. They aren't getting independent links from users. In short, these advertisers are using O'Reilly and other highly ranked sites who accept their advertising to improve their chances of being discovered via search engines, rather than in quest of direct click throughs (although those may also provide some value for their ad buy.)
# Google has an authorized way for people to show up arbitrarily high on searches: i.e., to pay for relevant Adwords. However, nearly all of the terms used in these links are quite expensive. So advertising on a site with a high page rank instead of via Google Adwords is a way of arbitraging the relative cost of advertising on the two sites. However, it has a downside in terms of the search engine user experience. The ad shows up as a sponsored link on the originating site, but as a legitimate result in the search engine.
Don't miss the conclusions at the end of the piece. This is a subtle and complicated issue.