Of course, these are all social graph problems at heart. Path—my all time favorite social network—was all ablut tiny communities of besties and/or families; LinkedIn is self-selecting professional relationships (effectively instance-based); Facebook and Instagram are basically just the whole of humanity, a few of which you’ve favorited; Google Plus (as well as I remember it), was very forward about allowing you to create different “circles,” but we all balked at the overhead of it all.