1. A method of matching a first user with a second user within a network of users, comprising: generating an ontology having a plurality of concepts arranged within a hierarchical knowledge profile; wherein the knowledge profile comprises at least a first upper-level tier and a second lower-level tier; wherein a user's interest in a concept located within the second lower-level tier subsumes interest in a broader concept in the first upper-level tier; and matching the first user and the second user as a function of their association with one or more concepts within the knowledge profile.