1. A computer-implemented method for identifying alternative merchant items, the method comprising: maintaining, by a computer, information regarding a plurality of merchant items; analyzing, by the computer, information regarding a plurality of queries to identify a plurality of merchant item-query pairs, each merchant item-query pair comprising a query and a merchant item that was previously selected from results for the query; for each merchant item-query pair, determining, by the computer, a number of times that the merchant item was selected from results for the query; for each merchant item-query pair, determining, by the computer, whether the query of the merchant item-query pair is associated with the merchant item of the merchant item-query pair based on the number of times that the merchant item was selected from results for the query relative to a number of times that results for the query were presented; analyzing, by the computer, the information regarding the plurality of queries to identify comparison queries directed to a comparison between two or more of the plurality of merchant items; and determining, by the computer, whether a first merchant item is an alternative to a second merchant item based on a number of times that a query associated with the first merchant item is included in a comparison query with a query associated with the second merchant item.