"...I'm horrible with deadlines for returning the cards to get what I do want and I hate dealing with returning things..."
This is what they're counting on. I learned my lesson many years ago by joining two of these clubs (one for novels and one for makeup). I'd forget to send back the card, then I would receive unwanted items. It was such a hassle to return them, and I hated it. I'll never join one of those clubs again.