You should never make someone pay anything, especially if they are helping you make money. I realize you don't make a lot from those that pay you to play their ads, but charging your players too? That's messed up. Especially when you know these people don't want to wait months for such a small amount of money. .... The payment only helps because that's how you wrote it into the programming. And the game may be free, but the players are working for the payments by watching the ads repeatedly.