You're the picture-perfect plastic user. You pay your bill in full each month. Heck, we'll even extend your credit so that you can get the stereo you really want. That's what your card issuer would like you to do. And impulse buys are how most folks get in credit card trouble in the first place.
Fools know that they'll pay a king's ransom in interest if they skip a month's payment.
Don't get us wrong. There are indeed reward cards that offer genuine perks like airline miles and football-shaped clock radios. With most, the rewards are based on the amount you charge, not your outstanding balance. Some even require cardholders to carry a balance to cash in on the perks. If you have the discipline, you can rack up some good points without going into debt, just like one of our favorite Fools, Dogwind.