At the same time, more and more people began to complain that being on the site made them unhappy. It should have been no surprise, given what we know about human nature and the way Facebook was first conceived to play on the social dynamics of anxious adolescents, but watching the highlight reels of other people’s lives was bound to make you feel inadequate. Others found Facebook (like email) a compulsion in that same Skinneresque manner—usually disappointing, but rewarding occasionally enough to keep you hooked. A variety of studies—none entirely conclusive, to be sure—associated depressive symptoms with Facebook usage, one finding that “compared to browsing the Internet, Facebook is judged as less meaningful, less useful, and more of a waste of time, which then leads to a decrease in mood.”

Tim Wu, The Attention Merchants, loc. 1012