1. A system for providing a recommendation for a game to game users, the system comprising one or more processors configured to execute computer program modules, the computer program modules comprising: a relationship graph module configured to maintain a relationship graph, the relationship graph including: a target user node representing a target user; one or more first layer game nodes each representing one of one or more first layer games, wherein each of said one or more first layer game nodes is associated with the target user node; one or more first layer user nodes each representing one of one or more first layer users, wherein each of said one or more first layer user nodes is associated with one or more of said one or more first layer game nodes; and one or more second layer game nodes each representing one of one or more second layer games, wherein each of said one or more second layer game nodes is associated with one or more said first layer user nodes; and a recommendation module configured to provide a recommendation identifying one or more of said second layer games to a client device of the target user.