Google’s Secret Display Advertising Network

John Chow has broken the story that Google has a ’secret’ CPM advertising network called the ‘Google Display Advertising Network’ which is an invitation only impression based ad network for high profile advertisers and a select group of publishers.
It apparently lets publishers negotiate their own CPM (cost per thousand impressions) with Google with year long contracts. The ads are image and video ads.
Google already do run CPM ads in their AdSense system but John is reporting that the rates that he’s managed to negotiate on his ad units in this program make those ads the highest earning ads on his sites.
The program seems pretty basic at this stage - reports come in via email once a week with very little information - sounds like it could be some sort of beta test or at least a pretty embryonic new ad network - definitely one to watch though!