There is a company that sells radar equipment to the police as well as radar detectors to the public. Clorox is one of the world’s worst polluters of water, and also sells Brita filters to get the bad stuff out of the water again. Lawyers create mazes that you have to hire a lawyer to escape. Similarly social software both creates and cures FOMO. If you didn’t know that party was going on, you’d be home contentedly reading your latest New Yorker. But since you do, you hungrily watch each new tweet.