Last November, Google told its AdSense publishers that it would be switching how it pays them for the Google Ads they embed on their websites. Now, it seems like many AdSense publishers are noticing that Google has completely switched over to this new payment model. Note that not all are switched from CPC to CPM bidding fully.
Personally, on my AdSense account, I am still seeing bidding using CPC, in addition to CPM:
But many are seeing CPM at 100% of their bidding earnings.
A WebmasterWorld thread has publishers talking about it since the start of this month:
It seems many of these publishers are hopeful that switching to 100% CPM will raise their revenues even though Google said it won’t change how publishers get paid.
Forum discussion at WebmasterWorld.
Update: Google’s Ads Liaison confirmed this:
