A method and system are disclosed allowing for determining those users of multiple users who satisfy desired condition(s), where characteristics of the users in at least some embodiments vary dynamically. In at least one embodiment, the method includes receiving at a server device a request for a determination regarding which of a plurality of users satisfies a plurality of conditions respectively relating to a plurality of user characteristics, and obtaining at the server device a conditions specification. Additionally, the method includes accessing at least one repository in which is stored information regarding the users to obtain at least some of the information, the information concerning the user characteristics. The method also includes making a determination regarding which of the users satisfies the plurality of conditions, obtaining at the first server device updated information from the at least one repository, re-evaluating the determination, and sending output information regarding the re-evaluated determination.