In a sign that Google’s contextual ads might not be nearly as useful to marketers as its search advertising, the company removed contextual placements from the tops of pages served by its free blogging tool Blogger. In the ads’ place is now a Google search box designed to increase search traffic.
The contextual ads ran over pages that Google’s servers deemed were relevant to the ad. Launched with great fanfare and hope, the contextual placements have not yet proved to be as targeted as paid search placements, where users have already self-selected themselves.
Seems to me that given the generally sprawling (and personal) nature of the content covered by blogs, Adsense would be a poor fit. Google searching however, could be an excellent match, since blog entries often prompt additional inquiries regarding specific topics.