16. Non-transitory computer storage having stored thereon executable program code that directs a server system that hosts a site to implement a Uniform Resource Locator (URL) rescue process for responding to a URL request received from a requesting device, said URL rescue process comprising: determining that a URL specified in the URL request is invalid; and at least partly in response to determining that the URL is invalid, executing a URL rescue strategy that comprises: mining, from a character string that follows a domain name portion of the invalid URL, a set of one or more search terms for executing a search of content of the site, wherein mining the set of one or more search terms comprises identifying at least one substring of the invalid URL and comparing the substring to entries in a selection list, the selection list including at least one of the following: a whitelist, a blacklist, a list of parameters; in response to successful mining of said set of one or more search terms, executing a keyword search of the content of the site using the set of one or more search terms, wherein the keyword search is executed using an index of the content of the site; and sending results of the search to the requesting device in response to the URL request.
17. The non-transitory computer storage of claim 16 , wherein sending the results comprises sending the results with a notification that a requested resource was not found.