Output URL Bidding

Output URL bidding is a new bidding mechanism for sponsored search, where advertisers bid on search result URLs, as opposed to keywords in the input query. For example, an advertiser may want his ad to appear whenever the search result includes the sites http://www.imdb.com and en.wikipedia.org, instead of bidding on keywords that lead to these sites, e.g., movie titles, actor names, and so on. In this paper we study the tradeoff between the simplicity and the specification power of output bids and we explore their utility for advertisers. We first present a model to derive output bids from existing keyword bids. Then, we use the derived bids to experimentally study output bids and contrast them to input query bids. Our main results are the following: (1) Compact output bids that mix both URLs and hosts have the same specification power as more lengthy input bids; (2) Output bidding can increase the recall of relevant queries; and (3) Output and input biding can be combined into a hybrid mechanism that combines the benefits of both.