CPM BIDS
CPM stands for “cost per 1000 impressions.” Advertisers running CPM ads set their desired price per 1000 ads served and pay each time their ad appears.
As a publisher, you’ll earn revenue each time a CPM ad is served to your page and viewed by a user. CPM ads compete against cost per click (CPC) ads in our ad auction, and we’ll display whichever ad is expected to earn more revenue for you
Other meaning.
Cost per 1000 impressions (CPM)
With this type of bidding, the advertisers state the maximum price for 1000 impressions. Contrary to the CPC type of bidding visitors do not have to click on the ads for you to earn some money. It is enough that the ad is technically loaded by visitors. “Technically loaded” means that the ad content is completely loaded on your site. It is not needed that the ad is actually visible on the current position of the browser window. Advertisers use CPM bidding when their goal is to get their name or logo in front of lots of people.
.In your Performance report you can see how much your site earned through this type of bidding if you choose the “Views” tab, which will automatically set the Bid types filter to CPM Bids.