Free games are only free not because they don't have costs but because people can download them anywhere at any time. In this case, Pokemon Go has virtual currency with a complex so people don't feel that they are spending real money. It is like paying in credit. Since it is fast and easy to get, people barely realize their spent their money. However, as some aspects of the games are difficult and time-consuming, people feel the need to have more virtual currency to get by. Basically, people who made Pokemon Go offer the easy way to success at a price. So ultimately, a small group of people pay a lot of money for virtual currency which keeps the game
