I realize that this won't be a popular opinion... But please realize that utilizing cards of these nature are making your everyday purchase more and more expensive.
Check out this site:
Unfair Credit Card Fees
Just a small excerpt from the site:
So you may seem like you are getting something for nothing, you aren't. We are all paying for your first class trips, your digital cameras, and your cash back.
I'm surprised someone hasn't torn you up about this yet actually. What about ATM fees, aren't they a scam too? We wind up paying for about anything these days one way or another, if credit cards were such a pain stores wouldn't accept them. Plus there are plenty of fools that keep balances on them and keep the business thriving by paying outrageous interest rates on the balance. If we all paid off our balances each month credit cards would probably not exist.