Relavent quote from article: "While talking to several members of the teenage\young adult age bracket, it became clear that the above results did not mean teen

Relavent quote from article: "While talking to several members of the teenage\young adult age bracket, it became clear that the above results did not mean teenagers did not use Facebook. Facebook, even if not their “primary” social network, continues to play a big role. It is, however, more of a utilitarian role than before." So Facebook has become akin to your public "phone book" listing for younger users. I don't think it's a matter of how often they "see" their friends, as Snapchat, Instagram and other app usage is very high so clearly - they want to connect in this manor - just not on Facebook.