Floor price
The minimum price a publisher will accept for an impression.
What is floor price?
A floor price, also called a reserve price, is the lowest bid a seller will accept for a given impression. Floors can be fixed per placement, or dynamic, changing according to signals such as geography, device, format, time of day, buyer or historical bid levels. They can be set in the publisher’s ad server, wrapper, SSP or within individual deals. Floors are a core lever of yield optimization: in first-price auctions they influence how buyers shade bids, and in deals they define the minimum agreed price. Hard floors reject lower bids outright, while soft floors were used in second-price auctions to adjust clearing prices.
How floor price works
Floors are set in the publisher’s ad server or supply-side platform, and bids below the floor are rejected.
- The publisher analyses historical bids and clearing prices for each placement and segment.
- Floors are configured by placement, geography, device, deal or buyer in the relevant platform.
- Each incoming bid is compared with the applicable floor.
- Bids below the floor are discarded, and the auction proceeds among eligible bids.
- Floor performance is reviewed regularly against fill rate and revenue.
Why it matters
Floors protect the value of inventory. Set too high they reduce fill; set too low they leave revenue uncollected.
For publishers
Well-set floors capture more value from high-demand inventory while still allowing remaining impressions to sell.
For advertisers
Floors signal the minimum cost of an environment and influence bid strategy, especially in deals with agreed minimums.
Practical example
A publisher sets a higher floor for its homepage placement than for article pages.
Key considerations
- Floors set too high reduce fill and can push buyers to other supply paths.
- Floors should be tested and adjusted rather than left static, because demand changes by season and market.
- Inconsistent floors across multiple platforms can produce unexpected auction outcomes.
More Publisher Monetization terms
Frequently asked questions
What is a dynamic floor?
It is a floor that adjusts automatically based on signals and historical bidding rather than staying fixed.
What is the difference between a hard and a soft floor?
A hard floor rejects any bid below it. A soft floor, used in second-price settings, allowed some lower bids to win at their own price.
Where are floors set?
In the ad server, header bidding wrapper, SSP or deal configuration, depending on the publisher’s setup.