Rumors have been swirling the last few weeks about Google offering impression based advertising (ads sold in blocks of 1,000 impressions). According to various media sources, Google is expected to make the announcement later today that AdWords advertisers will get some new options (ability to base pricing on impressions, purchase ads only on specific sites, etc.)
The upgrade is currently being beta tested with a few select advertisers, and should be available to all advertisers 2-3 weeks following the official announcement.
A new "site selection" tool is also rumored to be in the works that should make it easier for advertisers to find specific publishers they want to run their ads on.
