Glossary
What is Open auction?
Also called: open marketplace, open exchange
The open auction is the programmatic auction any approved buyer can join, bidding in real time for each impression above the publisher's floor.
हिंदी में पढ़ेंIn the open auction, an SSP or exchange offers each impression to many buyers at once. Any approved buyer can bid, there is no negotiated price or volume, and the highest bid above the floor wins. Google Ad Manager and most other exchanges now run first-price auctions, so the winner pays what it bid.
It sits at the bottom of the deal ladder. Above it come private auctions, which are invite-only and often have a higher floor, preferred deals, with a fixed price and first look, and programmatic guaranteed, with a fixed price and volume. Impressions that deal buyers pass on fall back to the open auction.
The open auction is where most remnant inventory is sold. Its prices depend on competition, on your floors and on the signals in the bid request, such as page, device and consent. Header bidding brings more of those buyers into the same auction at the same time.
Example
An impression goes to the open auction with a $1.00 floor. Bids arrive at $0.90, $1.60 and $2.10. The $0.90 bid is rejected and the $2.10 bid wins, paying a $2.10 CPM.
Why it matters to publishers
The open auction catches whatever direct sales and deals do not take, so competition and floors there directly affect your earnings.