2. The computer-implemented method of claim 1 , wherein selecting the third user with which the first user and the second user interact includes identifying that: (i) the first user subscribed to the third user so as to receive messages submitted by the third user, and (ii) the second user subscribed to the third user so as to receive messages submitted by the third user.
2. The computer-implemented method of claim 1 , wherein selecting the third user with which the first user and the second user interact includes identifying that: (i) the first user subscribed to the third user so as to receive messages submitted by the third user, and (ii) the second user subscribed to the third user so as to receive messages submitted by the third user. 4. The computer-implemented method of claim 2 , wherein selecting the third user with which the first user and the second user interact includes identifying that the first user has subscribed to another user who is connected in a chain of one or more subscribing users back to the third user.