So there is a secret Google advertising network and only elite publisher get to play, according to John Chow.
The Google Display Advertising Network was created so Google can go after Fortune 1000 companies, which buy advertising to build a brand more than to sell a product. Google already dominates text and CPC ads so going after display and video ads is the next logical step. Google offers display and video ads to AdSense publishers on CPC and CPM format already. However, the formation of the Display Advertising Network is a clear signal that Google really want to push this forward.
This is how disruption works — start at the low end and work your way up. Google is just doing it at hyper speed.
Link via Search Engine Journal