Barry Schwartz on SEL blog reports that Google is "retiring" AdSense "Onsite Advertiser Sign-up" feature. This feature, is referred to as the AdSense advertise on this site" feature, which allows AdWords advertisers to click on a link from an AdSense ad and specify they want their ads to show up on that publisher's site.
Google said the feature has "not been performing as well as we had hoped, and in the coming weeks the feature will be retired." Google first launched this feature back in September 2005 and many advertisers and publishers had high hopes for it. Any direct clicks on those "Advertise on this site" link will be directed to the AdWords sign-up page and no longer function as it once did.
AdSense, Google, Advertisers, Publishers
Google said: As the AdSense product evolves, we occasionally re-evaluate aspects of the product to make sure they are performing well for our publishers and meeting our goals. We found that the Onsite Advertiser Sign-up feature was under-performing, and so we have made the decision to focus our efforts on features that we believe will drive the best results for publishers.