For years, brand advertisers have been looking for ways to ensure their online ads are seen. This can be difficult — 56% of all display ads and 46% of all video ads aren’t viewable because they’re below the fold, scrolled out of view, or in a background tab. For several years, we’ve been working to help advertisers address this challenge and today we are introducing 3 key improvements: the upgrade of all CPM campaigns to viewable CPM campaigns; new viewable frequency capping; and supplementary reporting metrics built on the viewability standard. Google Moves to Improve Display Network Ad Viewability [adwords.blogspot.com]
Who bids CPM on GDN?
Why not just contact those sites directly, and do a direct Flat Rate / CPM buy?