I found some examples orren:
"A player that wagers 50 Euro 200 times on
Roulette will get 50 x 200 x .0050 = 50 Euro in cash back rewards added to their cashier
A player that spins a slot game for 1 Euro per spin 300 times will get 1 x 300 x .01 = 3 Euro in Cash Back Rewards added to their cashier
Remember folks, the rewards are instant and you get cash back for everyspin or hand played that reaches the betting requirement. The rewards are also ongoing, there is no cap on how much reward you can get. All awards come in 50euro cents increments."
For every 50 in bets you receive 0.50 (on all slots)
Hope this helps.
blue