Floor price

A floor price is the minimum bid a seller will accept for an impression, expressed in OpenRTB as imp.bidfloor, "minimum bid for this impression expressed in CPM," with its currency in imp.bidfloorcur.

Floors are the seller's pricing tool in a first-price world. A publisher or SSP sets them by placement, format, geography, buyer or deal, statically or with a dynamic model that learns from past clearing prices. OpenRTB 2.6 carries a floor on each impression, a separate floor on each deal (deal.bidfloor), and, since the 2.6-202309 snapshot, a DurFloor object for duration-based video and audio floors and bid-floor guidance (OpenRTB 2.6, sections 3.2.4 and 3.2.12; openrtb2.x releases). Prebid.js exposes the same idea to publishers through its Price Floors module (Prebid.org, Price Floors module).

Floors interact with bid shading: a buyer that shades below the floor loses, so sellers raise floors where they see shaded bids and buyers learn floors from ${AUCTION_MIN_TO_WIN}. They also interact with deals: a deal with at: 3 means "the value passed in bidfloor is the agreed upon deal price," which is how a fixed-price programmatic guaranteed line is expressed (OpenRTB 2.6, section 3.2.12). In a retail media network the floor is the reserve on sponsored-product auctions; Mirakl Ads, for example, exposes "floor price control per category" to the retailer (Mirakl Ads).

Example: "imp": [{ "id": "1", "bidfloor": 1.50, "bidfloorcur": "USD", "pmp": { "private_auction": 0, "deals": [{ "id": "DL-1", "bidfloor": 4.00, "at": 1 }] } }] offers the impression on the open market at $1.50 and to deal DL-1 buyers at a $4.00 floor.

Related: first-price auction, bid shading, deal ID, SSP.

Source: IAB Tech Lab, OpenRTB 2.6, Imp.bidfloor, Deal.bidfloor, DurFloor; Prebid.org Price Floors module.

1. OpenRTB 2.6, section 3.2.12
2. openrtb2.x releases
3. Prebid.org, Price Floors module
4. Mirakl Ads