A computer-implemented method comprises receiving a request for content from a user, determining two user lists that are associated with the user, each user list including a definition that characterizes members of a respective user list, determining a consumer is a subscriber to the two user lists, determining the consumer has indicated a preference to target members that are included in both user lists, and providing an indication to the consumer for all users that are included in both user lists including providing the definitions associated with both user lists along with the request to the consumer.