A system and method for selecting advertisements is disclosed. In example embodiments, a method includes submitting an offer to display an advertisement at a remote device, receiving one or more advertising bids, each bid indicating an advertisement and comprising bid amount, selecting a bid from the one or more advertising bids that results in a highest product, the highest product calculated by multiplying an estimated conversion rate for the advertisement indicated by the bid with the bid amount of the bid, and transmitting the advertisement indicated by the bid to the remote device for display.