There is often such a condition: you need to achieve a certain turnover, that is, for example, to make at least 100 bets for a certain amount. Only after that, if there is something left of the bonus, the player will be able to take the casino money for himself. Here is a concrete example: a player has received $ 100; to withdraw them (own funds can be withdrawn without restrictions), you need to make 100 bets of 10 each. All those funds that will remain on the balance and will be bonus, but played, can be withdrawn.