Systems and methods are disclosed for providing community-specific content to customers of a merchant's web site. In one embodiment, customers who are electronically referred to the merchant's web site from an affiliate web site, or from one of a group of related affiliate web sites, are automatically assigned to the same community. For example, all customers who enter the merchant's web site from links on golf-related affiliate web sites may be assigned to the community “golf.” Customers may also join or be assigned to communities using other methods. Purchase histories and/or other activity data of the merchant's customers is analyzed periodically to identify specific products or other items that are currently “popular” within the community (e.g., best selling), based upon predefined criteria. This information is provided to members of the community, and possibly to other customers, on the merchant's web site and/or on the web sites of the corresponding affiliates.