The Google team announced that AdSense will use a first price auction to make it easier to buy ad slots through the platform.
Adsense auctions for content, videos, and games with first-price rather than second-price rights will begin to be used in the coming months. The service’s Help specifies that this innovation is unlikely to affect the income of site owners.
Benefits for publishers and advertisers
A single, optimized auction model across AdSense, Ad Manager, and AdMob will help unify platforms in the display advertising ecosystem. Advertisers will have a better understanding of what constitutes digital ad spending, which will benefit publishers in the long run.
Preparing for change
The transition to the first price auction is scheduled for the second half of this year. The changes will take effect automatically, no further action is required.
For more information, see Adsense First Bid Auction FAQ
Source: Google Adsense Help