Abstract: A social dating system selects matching users for a viewing user based on common interests between the matching user and the viewing user. The social dating system accesses information related to users from a social networking system, indicating relationships between users and social networking objects. The social dating system determines common interests between users by determining a relatedness of social networking objects. The common interests are used to determine compatibility between users and to select matching users. Suggested messages are also selected for the viewing user to initiate a conversation based on common interests. The suggested messages may be based on promotions by an advertiser.