There's a story in here. The chapter about quitting on time usually feels like quitting too early. Stuart Butterfield who developed the game, video game people probably remember it Glitch. He realized that they were spending a lot of money to acquire new people and the churn rate was really high. So he quit early, returned the money back to investors that hadn't been spent but saved one feature from the game that people really loved which became a feature that eventually became Flickr.