A tracking system passively tracks and records searches conducted by actual search engine users. The recorded data for each search event preferably includes the search query submitted, the search engine used, the search result item (e.g., web page) selected, the position (e.g., page number) of this item, and the user's IP address. The collected data is aggregated and analyzed to generate data regarding the search queries used to locate and access particular destinations (e.g., web pages and sites). This data may be used for various purposes, such as (1) to, generate reports showing, e.g., how users reach a particular destination from different search engines and geographic locations, (2) to select content to display on a destination page, such that the content is relevant to search queries commonly used to locate that page, and (3) to update the database of one search engine to reflect searches conducted on other search engines.