Profit Checks are usually distributed at the really big wins in casinos to avoid handling cash. Profit checks are also widely used in land-based casinos, if you play on lottery games like a slot machine. After you are finished, you hopefully have some money left in the slot machine. Instead of collecting them as cash, the machine can print out a profit check equal to the amount you had in the game. The check can then be redeemed for cash at the checkout or simply fed into the next game machine if you want to continue playing casino. Practical and easy because you no longer need separate notes and coins.