29. The physical computer storage of claim 26 , wherein the items are catalog items represented in an electronic catalog.
26. Physical computer storage that stores executable code that instructs a computer system to perform a method that comprises: storing user activity data associated with each of a plurality of users of an interactive system that provides access to a data repository of information regarding items, said user activity data reflecting user-generated events associated with particular items represented in said data repository; identifying, among the plurality of users, a subset of users whose email addresses are associated with a particular organization; analyzing the user activity data associated with the plurality of users, including the subset of users, to identify, among said items represented in the data repository, a set of items that have experienced significantly higher levels of user activity among the subset of users than among the plurality of users; and storing, in computer storage, association data that associates the organization with the identified set of items.