Online social networks are used by hundreds of millions of people every day, but little is known about their effect on behavior. In five experiments, the authors demonstrate that social network use enhances self-esteem in users who are focused on close friends (i.e., strong ties) while browsing their social network. This momentary increase in self-esteem reduces self-control, leading those focused on strong ties to display less self-control after browsing a social network. Additionally, the authors present evidence suggesting that greater social network use is associated with a higher body mass index and higher levels of credit card debt for individuals with strong ties to their social network. This research extends previous findings by demonstrating that social networks primarily enhance self-esteem for those focused on strong ties during social network use. Additionally, this research has implications for policy makers because self-control is an important mechanism for maintaining social order and well-being.