What is a floor price in programmatic advertising?
A floor price (or reserve price) is the minimum amount a publisher will accept for an ad impression. Bids below the floor are rejected, even if they are the highest received. Publishers set floors by ad unit, country, device, buyer or deal, and increasingly use dynamic floors that adjust automatically based on demand.
Floor prices protect inventory value and prevent the impression from selling too cheaply. They interact with bid shading: buyers try to bid as low as possible, publishers try to set floors as high as the market will bear. Set floors too high and fill rate drops; too low and revenue suffers.
In the Google ad tech case, the court looked at how Google's "unified pricing rules" restricted publishers from setting different floors for different buyers. The EU also noted Google's November 2025 proposals included letting publishers set different minimum prices for different bidders.