COMPUTER SERVICES FOR IDENTIFYING AND EXPOSING ASSOCIATIONS BETWEEN USER COMMUNITIES AND ITEMS IN A CATALOG

A computer-implemented service associated with an electronic catalog analyzes purchase histories of users, and/or other types of activity data reflective of user affinities for specific items, to identify items that are significantly more popular in specific user communities than in a general user population. The communities may, for example, include email-based communities (e.g., all users with email addresses associated with a particular company), shipping address based communities (e.g., all users with shipping addresses in Seattle), and/or communities based on other types of user attributes. In one embodiment, a user of the service can select a particular community, such as by selecting the name of a corresponding organization or geographic region, to view a list of items having relatively high popularity levels therein. The results of the analysis may additionally or alternatively be used to affirmatively notify users of associations between particular items and communities, and/or to recommend items to users.