You might have remembered that mid-last year Google announced that it would allow 3rd-party networks to serve ads through its platform. What this meant, in practice, was that Google offloaded a lot of Doubleclick inventory onto its AdSense publisher base. We noticed a large uptick of AdSense ad spots on the top 100,000 Websites suddenly serving Doubleclick ads in the second half of November 2008—the number of AdSense ad units serving up Doubleclick inventory more than quadrupled.
What a tighter AdSense-Doubleclick integration also allows is display/rich-media formats innovated by the latter to be displayed across AdSense’s vast publisher inventory. Google has just announced on its official AdSense blog that it will begin to show expandable ads, naturally, as third-party ads that publishers must set their accounts to allow.
In the post, they make it clear that while visitors can provide easily-demonstrable engagement with the ad by choosing to expand it, publishers are only paid if a visitor clicks on the ad to taking it to the landing page. No word if Google if remunerated by its advertisers by the same metric.