Gift cards are popular in Pittsburgh because shoppers can earn gas discounts if they buy the cards at area supermarkets. But the faltering economy may be making the gift more of a risk.

They could become unusable as more and more stores go out of business. That's what happened when Sharper Image went under this year-- customers were left holding an estimated $20 million in unused gift cards.

Point Park marketing professor Paige Beal told consumers to buy the cards with caution.

"You don't know what retail location is going to be open after Christmas. If we know right now these other stores have gone down after Christmas there is a greater likelihood we're going to be seeing more bankruptcies," said Beal.

Buyers need to be aware of businesses that may be in trouble. Click here to see which retailers are having financial trouble.

Circuit City filed for Chapter 11 bankruptcy, but said it's still honoring gift cards and still selling them.

The electronic chain is also closing 155 stores so you may have a harder time finding a store to spend that card.

And if the company goes under, the gift cards most likely become worthless.

If you still want to give gift cards, experts say give ones that'll be used quickly, like cards for food or gas.