Buyers and Google prefer 2nd-price. 1st-price is happening because the industry forced it with publishers doing header bidding to create a unified auction. The

Buyers and Google prefer 2nd-price. 1st-price is happening because the industry forced it with publishers doing header bidding to create a unified auction. The only way to compare multiple separate auctions is if the original bids carried through. Now all the complexity has shifted to buy-side platforms with "bid shading" and other algorithms.