The cashback bonus is another great incentive that many online casinos offer to their players. We have a complete list of all the biggest online casino cashback bonuses on this page. These bonuses are usually given as special promotions when players reach specific milestones. Sometimes they are given to all players within a short time window. The concept is very simple, and it helps offset loses. With a cashback bonus, players are given a percentage of their wagered money back within a set time period. For example, if you wager $1000 and the cashback bonus is 15% then you will get $150 back.