A closer look at retail credit cards

SEATTLE -- When you're out and about shopping between now and Christmas, there's a good chance the clerk at the register will ask you, "How'd you like to save an additional 10- to 15-percent off your entire purchase?"

All you need to do is apply for the store charge card and you get the discount.

What do you do? What should you say?

"I know that it's very tempting, but always say no," said Beverly Harzog of "Ask to take an application home with you, so that you can read the fine print."

Harzog said without knowing all the details, you won't know what you're signing up for.

"It's just never, ever a good idea to try to get approved on the spot when you haven't even read the fine print," she said. "You don't even know what the card is about. You don't know the interest rate or if there's a grace period. There are just so many things you need to know first."

Some retailers offer their version of a Visa and Mastercard. Others, like Macy's the Gap and Best Buy, have their own cards that can only be used in their store. If you're a regular customer, you may want to consider getting it for the special deals that aren't available to the general public.

But consider this: Cards offered by retailers tend to have the highest interest rates -- usually 10 points more than a regular credit card.

An interest rate of 22 to 24 percent (or higher) would more-than erase any on-the-spot savings you'd get if you applied for the card, bought the merchandise and then didn't pay off the balance in full.

Remember, any time you apply for credit, it lowers your credit score.

"It's going to ding your score just little bit. It's not a lot, a maybe a couple of points, but still, why even have that happen if it's not a card you're going use again or is a card that is not going to meet your needs," Harzog said.