Friend-of-friend algorithm leverages only social network information of friend-ing based on the intuition that “if many of my friends consider Alice a friend, perhaps Alice could be my friend too”. Many social network analysis approaches have
adopted similar ideas to find neighborhoods and paths within the network [5, 6, 7].
This particular variant that recommends friends of a friend is interesting not only
because of the clear intuition behind it, but also because, as implied in the official Facebook blog , it is the primary
algorithmic foundation of the “People You May Know” feature on Facebook, which is one of the few known people
recommend deployed on a social networking site.