The way the "slots" at turning stone work is when you sign up for a slot card you also select a PIN number. You can then purchase credits at the cashier windows which are credited to your account. To play you insert your card and enter your pin number. When you are done you bring your card to the cashier and you can withdraw any credits remaining.

The cards Don scanned are promotional. They are given to players for free. They contain credit for the amount listed on the face, the catch is that you can only cash out once with those cards and you can only receive the amount of credits on the card over the starting amount. So If you receive a $25 card after playing you have $30 credit on it you only receive five dollars.

I believe that I have seen other varietys of these cards. Because I don't collect slot cards I usually just throw them out. I will try to remember to pick some up for you guys next time I am out there.

BTW I have an extra of the Diamond Club Card if anyone wants it.