25. A non-transitory computer readable storage medium storing at least one program configured for execution by at least one processor of a computer system, the at least one program comprising instructions to: receive a search query from a user; identify a set of ranked search results satisfying the search query; identify, using historical search query data, at least one last related search query in at least one chain of related search queries that is related to the search query and that includes at least one search result that was selected by users who issued the search query, wherein the identifying includes querying a query database to identify the at least one last related search query in the at least one chain of related search queries that are related to the search query, wherein a respective chain of related search queries is a sequence of consecutive search queries that are issued by a respective user and that include an initial search query that is successively refined; the query database includes a plurality of records, wherein each respective record includes: a respective search query; a number of times the respective search query was issued; a respective search result that was selected by users who issued the respective search query and that corresponds to at least one respective related search query in at least one respective chain of related search queries that are related to the respective search query; the at least one respective related search query; and a number of times the respective search query led to a selection of the respective search result; and return the set of ranked search results and the at least one last related search query to the user.
25. A non-transitory computer readable storage medium storing at least one program configured for execution by at least one processor of a computer system, the at least one program comprising instructions to: receive a search query from a user; identify a set of ranked search results satisfying the search query; identify, using historical search query data, at least one last related search query in at least one chain of related search queries that is related to the search query and that includes at least one search result that was selected by users who issued the search query, wherein the identifying includes querying a query database to identify the at least one last related search query in the at least one chain of related search queries that are related to the search query, wherein a respective chain of related search queries is a sequence of consecutive search queries that are issued by a respective user and that include an initial search query that is successively refined; the query database includes a plurality of records, wherein each respective record includes: a respective search query; a number of times the respective search query was issued; a respective search result that was selected by users who issued the respective search query and that corresponds to at least one respective related search query in at least one respective chain of related search queries that are related to the respective search query; the at least one respective related search query; and a number of times the respective search query led to a selection of the respective search result; and return the set of ranked search results and the at least one last related search query to the user. 28. The non-transitory computer readable storage medium of claim 25 , wherein each respective related search query in the at least one chain of related search queries, except for the at least one last related search query in the at least one chain of related search queries, violates a timing criterion with respect to user-selection of search results.