I assumed that before bidding, DSPs could not be sure whether an SSP applies floor price rules to an auction. Now, I saw some remarks in the academic literature implying that buyers know about the existence or even the exact quantity of floor prices.
In practice, do SSPs communicate their floors?
This question was asked on quora, below is my answer.
The answer is: sometimes. Exchanges sometimes express floor or bid guidance in the bid request. This is not required for the market to operate; so many exchanges do not provide any guidance. Floors are almost always in play. In most cases they are dependent on a wide variety of variables including: the site, browser, device, day of week, time of day, audience data, user’s language, and geographic location of the user.
Floor prices, from an academic standpoint, are there to protect the base value the publisher has placed on the inventory. Bids falling below the floor, or reserve, are usually rejected by the exchange. Losing bid information might be recorded to give the publisher insight on the value advertisers are placing on the inventory and accompanying traffic. Next: Price Floor Discovery