The world of credit cards is getting more complicated, if that's possible. More and more retail stores are teaming up with American Express, MasterCard or Visa to issue credit cards that carry the name of the store and the logo of the card issuer. But they also still offer cards that can be used only in their own stores. How does a consumer choose?

With the GapCard -- accepted at Gap, Banana Republic, Old Navy and piperlime.com -- you earn 5 percent in rewards on all purchases at any of those stores, free standard shipping on all online purchases over $100, and 10 percent off any purchase "the first Tuesday of every month," among other incentives, big and small, that come and go as the Gap companies work to keep their customers coming back for more.

Known as private-label credit cards, the one-store-only cards have introduced reward programs that pay cardholders to use their cards again and again.

"Private-label cards used to be pretty plain vanilla; they charged interest, you could use them to buy in that store, and that was it," says Margaret Keane, president and CEO of the retail consumer finance division of GE Money. "Now, more and more, you're seeing retailers look at how they can reward their customers to get them back in the store to spend more."

"For instance, they'll give their Gap cardholders $10-off coupons or 20 percent off at different times in the year -- those kinds of things," Keane says.

Compare the 2 types of cards

Private label: Co-branded cards: Easier to qualify. APR depends on credit rating. One high APR for all. Variable APR, lower than private label. Low credit limit. Credit limit depends on rating. Use only in one store. Use anywhere. Rewards for shopping in store. Rewards for shopping anywhere.

In the store and beyond
Nowadays, private-label cards have company.

Co-branded cards that sport the names of Gap, Target or eBay and have a Visa or MasterCard logo firmly planted in one corner are doing their part to increase in-store sales, as well.

"And purchases made with the Best Buy Reward Zone MasterCard earn 4 percent on Best Buy purchases and up to 2 percent on purchases everywhere else," says Cindy Savio, a spokeswoman for HSBC.

Holders of Visa co-branded GapCards, for example, receive all the benefits of the Gap's private-label cards plus the ability to earn 1 percent back on all their purchases anywhere Visa is accepted. EBay cardholders earn points on their MasterCard purchases that they can use to pay their membership and other fees on eBay.

Share the risk
HSBC issues the Best Buy card, among others. GE Money is the issuer of a number of co-branded cards, including the eBay and Gap Visa cards and a Dillard's American Express card. Chase Card Services is another major player, with a list of private-label and co-branded cards that includes Starbucks and Herbalife.

For the retailers, the upside of having a large credit card issuer as a partner is to share the financial risk.

On the other hand, Target and Nordstrom issue their own co-branded and private-label cards through their subsidiary banks.

"Over the years, most merchants have gotten away from direct issuing either private-label or co-branded cards," says Ken Paterson of Mercator Advisory Group.

In any case, there are generally some key differences between the two types of programs. For one, it's easier to qualify for a private-label card because of the control the store has and because the credit limits are typically much lower than on a co-branded card.

"Also, the credit underwriting standards for co-branded cards like the Target Visa card are going to be different because the customer can use it in so many places besides Target," Paterson says. "So they need to be more careful in their underwriting."

Check the APR
Of course, you'll usually find a higher APR on a private-label card than on a co-branded card from the same store. The Target credit card, for instance, comes with a 24.24 percent APR. The APR on a Target Visa credit card, on the other hand, will depend on your credit rating. It starts as low as 13.24 percent and tops out at 22.24 percent.

Store card or co-branded card?

Questions to ask before you sign up:   • What is the APR? • What is the credit limit? • Is there a reward program? • Can you manage the account online? • Does the card have zero-liability protection?

In any event, the APR will always be lower than the private-label card.

"Co-branded card customers probably look more closely at what rate they're getting than they do on a private label card, especially if they know that their credit is good," Keane says. "They're not going to take a rate that isn't good." Well, they might -- if the rewards are good enough.

Which card you choose ultimately depends on your shopping habits.

"Some women -- I can say this -- like to compartmentalize their spending," says Keane. "There are people who like to keep their gas purchases on their gas card or their clothes buys on their Dillard's card, because they want to compartmentalize what they spend, and they want to be able to spend whatever they want and not have anyone (read 'their spouse') question their purchases."