1. A system comprising: a receiving module to receive, over a network, a request from a user in a community of users, the request related to an activity associated with a listing for sale in a network-based marketplace that is used by the community of users to transact listings of a single domain that is of interest to the community of users; and a reputation module to update a listing reputation score for the listing based on a user reputation score for the user and to update the user reputation score based on the listing reputation score.