That makes sense.. however winner's curse is more relevant when you have common value auctions (eg: bidding for something with an unknown value that is the same

That makes sense.. however winner's curse is more relevant when you have common value auctions (eg: bidding for something with an unknown value that is the same for everyone). However, in advertisement everyone has a different value derived from the ads, and also since you advertise every day, winner's curse is less likely (you learn). =)