1. A computer-implemented data mining method, comprising: storing, in an electronic data repository, user activity data associated with each of a plurality of users of an online system that provides access to an electronic catalog, said user activity data reflecting user-generated events associated with particular items represented in the electronic catalog; programmatically identifying, among the plurality of users, a subset of users whose email addresses are associated with a particular organization; programmatically analyzing the user activity data associated with the plurality of users, including the subset of users, by execution of code by a computer processor, to identify 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 creating, in computer storage, an association between the organization and the identified set of items.
1. A computer-implemented data mining method, comprising: storing, in an electronic data repository, user activity data associated with each of a plurality of users of an online system that provides access to an electronic catalog, said user activity data reflecting user-generated events associated with particular items represented in the electronic catalog; programmatically identifying, among the plurality of users, a subset of users whose email addresses are associated with a particular organization; programmatically analyzing the user activity data associated with the plurality of users, including the subset of users, by execution of code by a computer processor, to identify 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 creating, in computer storage, an association between the organization and the identified set of items. 10. The method of claim 1 , wherein programmatically analyzing the user activity data comprises applying an algorithm that identifies items that distinguish the subset of users from users whose email addresses do not reveal an association with the organization.