Of all the implications Google advertisers, users, AdSense publishers, advertisers, and observers have had to absorb today, the most far-reaching is that Google's new advertising program has nothing to do with search. Google can no longer call itself a search company, at least not entirely. My definition of Google has always been a keyword processing company. The core mission has been to match people with information, and buyers with sellers, by hinging a perfectly relevant keyword between them. With the Site Targeting plan, Google shockingly puts relevance (which used to be the company's most sacred principle) in the hands of its advertisers.

Google is trusting the advertiser's motivation to target ads to relevant sites, but Google has never before trusted the advertiser to make that judgment. The AdWords method has always been to automatically sever the connection between any underperforming ad and its keywords, curtailing the appearance of that ad. Google's technology was the sole arbiter of relevance, and that relevance was determined by clickthrough rate. Now, placing ads on advertiser-determined sites, with payment by the impression, ad performance is no longer a viable concept. Accordingly, any advertiser with the loony idea that motor oil will sell on an environmental activism site can outbid competitors and place that ad. And Google's reputation for relevance gets poured into the ground.

Much has been said today of Google reviving the ad network concept—a second coming of DoubleClick. What happens to trust if Google becomes merely an ad broker? What does Google do in the future to continue earning its position as a leading ad network? CPM advertisers are competing with PPC advertisers for the same ad inventory, and Google is clearly courting the big bucks of brand advertising. If Google's new advertisers consistently outbid relevance, and push relevant advertising out to the fringes, what happens to Google's reputation—once its core asset?

Going public is a bitch. It always distorts. Wasn't there something about evil in the filing papers? I'm not a big "good and evil" guy. But if Google has stepped off the path of keyword processing, off the path of relevance, then certainly its core mission is challenged. Google might not be heading down a path that makes it evil, but neither it is a path that makes it Google.