Also Team Fortress 2 make 3x more money for 2 reasons. It's Valve, which has a HUGE fan base, and they sell crate that contains a random hat, which can be sold for money to someone else (in the end it act like a lottery where people think they will be able to get a rare hat that will be sold for hundreds of dollars on the market). I don't think you can reproduce these two things on every game.