3. Traditional cards may offer more substantial rewards.

Sure, you're getting a discount with a store card, but you're forgoing the points you would be getting if you charged your purchase to a lucrative traditional card that offers travel points or cash back, Kelly says.

"Yes, you're saving $40, but you're losing the American Express  (AXP) or Chase  (JPM) points that might help you get a free trip that would be worth way more than that discount," he explains.

Free gift certificates throughout the year may be another item stores offer to sweeten the deal of their branded credit cards, but the savings won't often be much more than 20% to 30% at any point, Kelly says.

If you're still having trouble knowing exactly which rewards are better for your buying habits and lifestyle, Odysseas Papadimitriou, founder and CEO of Evolution Finance, the parent company of CardHub.com, says it's best to use a cash comparison.

"It's very had to compare miles with points, etc. so the best option is to convert everything to cash and then see what's going to offer the most bang for your buck," Papadimitriou says.

4. Many store cards have deferred interest.

What it often comes down to is that the short-term discount that you would get from opening a card is not worth the high interest -- often exceeding 24%, Albery says. Many store cards that appear to offer zero-percent interest actually offer "deferred" interest -- so if you miss a payment or you can't pay your purchases off in full, those interest rates kick in.

"Even if you miss a payment by a couple of days, they go back and assess your interest rate as if they never gave you that zero-percent rate," Papadimitriou says. "So even if you have paid $480 towards a $500 TV, they will go back and charge you interest on the full $500 purchase."

Although deferred interest isn't unique to store credit cards, it is more common, Papadimitriou says, adding that the zero-percent offers are often used as a way to "get consumers on the hook."

5. Store credit cards are easier to get and reward regular customers.

"At the end of the day, store credit cards are easier to get than the premium travel cards, so they may be a good option for people looking to build credit," Kelly says.

Because a store credit card counts as a different line of credit on your credit report, people just building credit can benefit from having different lines of credit available to them.

Also, if you're a frequent shopper, some cards may be just what you're looking for.

"If you shop at Target  (TGT) frequently, for example, their card gives 5% off virtually every purchase plus makes a charitable donation to the school of your choice," Detweiler says. "I can't think of another card that gives 5% cash back on every purchase."

Additionally, the Kohl's card may also be a good deal for frequent shoppers, Kelly says. Once you spend $600, you'll be eligible for 18 different deals and discounts throughout the year.

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