When all prizes are redeemed, you have some prizes. They are called net revenue. For instance, when a business has $200 in sales and $100 in prizes, you are left with $100. And yes, this is your net revenue.
And the percentage that you’re left over with after redemption of all prizes is called a hold. For example, your business has $200 in sales, $100 in prizes, so you are left with $100. The hold is $100.