Sticky Bonus :
A sticky bonus is a bonus that cannot be cashed out. T he bonus amount can be used to bet with but the bonus part will be removed from your account when you make your first withdrawal. Sticky bonuses are also known as "non-cashable" and "for wagering purposes only" bonuses.
Example: you deposit $100 and receive a $200 bonus (200%). You play until you have $750. When you withdraw the money the casino will remove $200, leaving you with a payment of $550.