Some retailers try to lure you into opening a card account by offering a 10 to 15 percent discount on all purchases made on that day. If you're buying a lot, the savings can be an incentive, though there may be a cap on the amount you can spend, and the discount doesn't apply to all the subsequent purchases you'll make with that card.
But you should avoid opening several credit-card accounts at once--a common holiday-shopping pitfall--because it could cause your credit score to drop. And since some store cards have very low monthly credit limits, you might end up charging close to the limit. That will increase your debt-to-available credit, which can also lower your score.
Opening multiple card accounts in a short period could also reduce the average length of your credit history, a component that makes up about 15 percent of your score. If you open just one store card to take advantage of the up-front savings on a large purchase, that might drive your score a bit lower temporarily.
And if you can't pay your monthly balance in full, the interest you'll be charged could wipe out the discount you got for signing up for the card. The average bank credit card has an interest rate of about 15 percent, but cards from Bloomingdale's, Macy's, and Sears have interest rates of about 25 percent. Some store cards, like those offered by JCPenny, HomeGoods, Marshalls, and T.J. Maxx, are even higher, 27 percent, while NAPA Auto Care, levies a whopping 30 percent interest rate.