You got it!!! You're going to love collecting them also. You can also discretely "pick up" extras you find laying around that previous owners didn't want any longer. You can use those for trading.
When couples go shopping for strikes, the other half can go looking for card dups. Sometimes you'll find older ones you can't get from the slot clubs any more....but discrete is the word as some casinos frown on the practice.
Actually you'll probably want to use your own slot cards whole playing the silver strike machines to earn credits. Most machines you can't use them though. HAVE FUN!!!