Abstract: Methods, computer systems, and computer-storage media are provided for ranking ads. A reserve price is included in a calculation of a score to rank one or more advertisements for display. The calculation may further rely on a bid submitted by an advertiser for an advertisement, a click probability associated with the advertisement, a relevance of the advertisement to a search query and/or user, and the like. Once the reserve price is used to establish a score for one or more advertisements, a price is calculated for each of the one or more advertisements. The one or more advertisements may be displayed in an order indicated by the scores of each of the advertisements.