In programmatic advertising, a unified auction is a type of auction in which multiple demand sources (e.g., ad exchanges, demand-side platforms, and ad networks) compete to serve an ad to a particular user. In a unified auction, all of the demand sources submit bids for the ad impression at the same time, and the winning bidder is determined based on the highest bid and the ad exchange's rules for ad selection.
Unified auctions are generally considered to be more efficient and transparent than traditional ad auctions, as they allow multiple demand sources to compete on a level playing field and offer advertisers more control over where their ads are shown. They are also often used in conjunction with real-time bidding (RTB), which allows advertisers to bid on ad impressions in real time based on the specific characteristics of each user (e.g., demographics, interests, and location).
Unified auctions are an important part of the programmatic advertising ecosystem and help to ensure that advertisers are able to reach the right audience with their ads at the right price.