This type of bonus doesn't usually come with wagering requirements as you've spent the money at the casino once. Hence, instead of the casino giving you money, like with a deposit deal, you're getting some of what you've already spent back. However, it's unlikely that any gambling site would allow you to withdraw cash back credits; instead, they may be “sticky,” meaning you can only use the funds to play more. To find out the exact rules of a bonus, in regards to cashback bonuses or even welcome bonuses, make sure to always check the terms and conditions.