Google has dropped the Onsite Advertiser Sign-up feature, better known among advertisers as the "advertise on this site" component of AdSense. According to a report at TechCrunch, the reason is simple: Google's computers do a better job of placing ads than humans.

In a post at Search Engine Land, Barry Schwartz broke the news that Google had not been pleased with the performance of the feature, which launched in 2005.

"As the AdSense product evolves, we occasionally reevaluate aspects of the product to make sure they are performing well for our publishers and meeting our goals," Google said in a statement. "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."

In this case, it seems a marketer's hard-won knowledge is no match for the AdSense computers, which automatically measure response rates and make adjustments when needed.