There is a news from Adsense. Adsense has started to put image ads in the link units. These are the ads that a user would see after it clicks a link unit topic. Currently the ad is in bottom of the page that a user hoes to after clicking.
Says Adsense blog
If you use link units, you may have noticed a small addition to the page users see after clicking a link unit topic. We recently added an image ad to the bottom of each of these pages, after our testing showed revenue improvements for many publishers.
Here is a shot [Read more...]