That's a laugh...giving you back goods/services that they can write off. The longer you give them to beat you out of your money the more you get. 25,000, 50,000, 75,000 points holders--Will you please tell me how much of your winnings you have stored away in a bank, CD or mutual fund?! Not to worry though, you can get a room or a gourmet restaurant meal anytime you want--just be sure to put your money on the table or in the slot machine.
Having worked in the industry I developed a philosophy of playing sensibly and taking whatever winnings I can amass and LEAVE; I can't take a $15 buffet comp or free room that cost the casino nothing because it is there anyway, to the bank. The law of averages is on their side!
However, on the positive side, casino comp/player cards are great collectibles.