14. A computer-readable storage medium having instructions stored thereon that enable at least one processor to perform a method upon execution of the instructions, the method comprising: identifying one or more queries based on one or more topic-relevant seed uniform resource locators (URLs), a record of previously submitted queries and selected URLs, and one or more additional URLs derived from one or more queries associated with the one or more seed URLs, wherein one or more additional queries of the one of the one or more queries identified from the additional URLs are not directly associated with the one or more seed URLs in the record; determining a co-occurrence score for one or more keywords comprising the one or more queries; determining a lexical generality score for the one or more keywords; and saving the one or more keywords, and co-occurrence and lexical generality scores to a persistent store.
14. A computer-readable storage medium having instructions stored thereon that enable at least one processor to perform a method upon execution of the instructions, the method comprising: identifying one or more queries based on one or more topic-relevant seed uniform resource locators (URLs), a record of previously submitted queries and selected URLs, and one or more additional URLs derived from one or more queries associated with the one or more seed URLs, wherein one or more additional queries of the one of the one or more queries identified from the additional URLs are not directly associated with the one or more seed URLs in the record; determining a co-occurrence score for one or more keywords comprising the one or more queries; determining a lexical generality score for the one or more keywords; and saving the one or more keywords, and co-occurrence and lexical generality scores to a persistent store. 19. The method of claim 14 further comprises: submitting at least one query extracted from the record based on the one or more topic-relevant seed URLs to a search engine; acquiring the one or more additional URLs returned from the search engine as search results; and extracting one or more other queries from the record for the one or more additional URLs.