Google announced that by the end of the year, Google will move AdSense from second-price to first-price auction. Google said they expect this to have a neutral impact on AdSense publishers' earnings overall. As a publisher, there is nothing you need to do - this happens on its own.
Google said this change will "make it easier for buyers to purchase your ad space sold on AdSense."
Why the change? Google said "in the early days of online display advertising, ad space was sold to advertisers in a second-price auction, where the final price paid by the winner was determined by the amount of the second-highest bid. Over time, many ad selling platforms in the display advertising ecosystem, including Google Ad Manager and Google AdMob, switched their auction to first-price. In a first-price auction, the final price reflects the winning bid. In the coming months, AdSense will move to a first-price auction. This will help advertisers by simplifying how they buy online ads and make it easier for them to buy your ad space sold on AdSense."
This benefits publishers by "streamlining the auction model across AdSense, Ad Manager, and AdMob," Google said. Google expects this to help advertisers trust the platforms more and increase advertiser spending confidence.
This impacts AdSense for Content, AdSense for Video and AdSense for Games but does not impact AdSense for Search or AdSense for Shopping.
How will this impact your earnings? It probably won't said Google, who wrote "on average we expect the impact to AdSense publishers' earnings overall from the move to a first-price auction to be neutral. When Ad Manager moved to a first-price auction, there was a neutral to slightly positive impact to publisher earnings on average."
I do suspect Google will make more money from this but they won't admit that...
There is no question this helps Google make more money. Second price meant the winner didn’t ever overpay, now they can. You can tell this is good for big G because the blog post is short and vague. When they want to explain something they’re thorough. In this case they don’t.
— Darshan (@darshan) October 7, 2021
Forum discussion at Twitter & WebmasterWorld.