A system and method for automatically determining library patrons' interests without having to identify the patron or otherwise invade his/her privacy based on the library patron's current use of library assets. The system and method involve categorizing the library's assets using broad mapping user interest categories, associating a user interest category with a specific library asset that is checked out, reserved or otherwise used by a library patron and providing that patron with a confirmation item containing that user interest category, providing the library patron with feedback about the library assets and the broad mapping user interest categories, allowing library patrons to access and register for a library rewards program using the user interest category number and having advertisers provide relevant information and rewards to library patrons who request such additional information.