Every big store hawks its own credit card.

Cashiers try to lure you into applying with 10% discounts, invitations to special events, advance notice of sales, or no interest until 2009.

But if you want to manage your credit cards like a pro, you should only have two or three -- not a wallet full.

The smartest choices are major cards with lower rates and better rewards than store cards can offer.

Here are the 7 reasons to resist store credit cards:

Reason 1. Higher interest rates Store cards typically charge interest rates of 18% to 23% a year. The average rate for a major credit card is about 14.5%. Carry a balance of $2,500 on a store card and you'll pay an extra $200 a year in finance charges.

Reason 2. Limited perks. Higher interest rates can quickly wipe out whatever rewards you earned for signing up or spending all of that money. And racking up lots of points on your Pottery Barn card won't do much good if you fall in love with a Crate & Barrel sofa. Bottom line: Any of the deals on our list of the best reward cards will provide more generous, satisfying benefits.

Reason 3. Incessant appeals to spend, spend, spend. Research shows that shoppers with store cards spend three times more than other customers. Merchants encourage that by watching what their cardholders buy and plying them with targeted advertisements and sales. The reward programs are designed to make you think "What else can I buy to earn that next gift certificate or discount?"

Reason 4. Deceptive promotions. Who hasn't heard a come-on like this: Charge your refrigerator, wide-screen TV or dining room set to a store card and pay no interest for a year, or even longer? Sounds great, eh? But these deals come with a huge catch. If you don't pay off every cent of that purchase by the deadline date, you'll be billed for all the interest on the entire purchase price, dating back to when you bought it.

Reason 5. Heaven knows what you're signing up for. Impulsively applying for a store card at the cash register or promotional kiosk is a rushed, thoughtless process. You'll almost certainly miss all the costly fees and terms buried in the fine print -- from sky-high penalty rates and short grace periods to two-cycle billing.

Reason 6. Lower credit score. Each time you apply for a credit card, your credit score dips about 10 to 15 points. You'll suffer even more if you have lots of other cards and are adding to a hefty line of available credit.

Reason 7. Co-branded cards aren't a big improvement. The latest trend is for retailers to offer their own version of major cards, such as the Chase Amazon Platinum Visa, Sears Gold MasterCard and The Knot Credit Card from American Express.

Sure you can use them everywhere major credit cards are accepted. But any rewards must still be redeemed at the single sponsoring store and the deals are unimpressive.

Take the Chase Starbucks Duetto Visa Card, for example. You earn $1 in Starbucks Duetto Dollars for every $100 you spend, which is not as rewarding as cash rebate cards that return up to 3% on some purchases. A cash rebate can also be spent anywhere, not just at Starbucks.

The card charges no interest on purchases for six months. But then rates climb to a steep 15.24% to 23.24% (depending on your credit history). It also imposes some very unfavorable terms including universal default and a 3% balance transfer fee of up to $99.

In short, your best bet is to keep your wallet sleek and trim by relying on one or two low-interest or truly rewarding major credit cards.

By Tracy Needham

Interest.com Contributing Editor

Have a question about your finances? Ask us at editors@interest.com