What is Second Price Auction?

A Second Price Auction (sometimes referred to as a Vickrey Auction) is where each bidder submits a bid which is the highest amount they are willing to pay. The highest bidder wins but the price paid is the second-highest bid plus $0.01.

For example, if the highest bid is $9 and the second highest bid is $5.55 then the highest bidder pays a clearing price of $5.56

In a second price auction, the advertiser expects to have their price reduced.