From time to time a limited-time offer will pop up - the Cashback Promotion. This allows you to get back a certain percentage of all future bets, which ultimately saves you a lot of coins and allows you to bet higher!
All details regarding the various aspects of the offer are detailed in the Cashback Popup, individually.
You can purchase this promotion through the in-game popup offers. Normally, you will receive a popup with your Cashback payment within 2 days after the promotion has ended.