As part of the transition to a unified first-price auction, buyers now have access to minimum bid to win (minimum_bid_to_win) after an auction. Minimum bid to win specifies the amount that the buyer would have needed to pay to win the auction. Sharing this information helps buyers bid more competitively, which can improve your yield.
When you additionally have a mediation chain, allowing buyers to access analogous data further help in improving competitiveness among buyers and could increase your yield. Starting the first week of October 2019, a model that generates random samples to represent eCPM from potential mediation competition will be shared with buyers, informed by the eCPM and fill rate for the mediation chain, from demand sources that are placed before and after buyers.