Starting Christmas Day, Wal-Mart is letting customers exchange gift cards from more than 200 retailers, airlines and restaurants for a Wal-Mart card. The cards don't expire and can be used in stores and online.

It's a test program, but if it's successful, Wal-Mart Stores Inc. said the card swap could become a permanent service. Wal-Mart spokesman Ravi Jariwala said the chain doesn't have specific metrics to evaluate that but will watch how shoppers react.

Shoppers won't get the full value of their gift cards to use at Wal-Mart. For example, with Amazon.com, customers can redeem up to 95 percent, while for Staples that figure is up to 90 percent and for Gap, up to 85 percent. For some brands, a Wal-Mart gift card will be worth just 70 percent of the original card.

To exchange a card, go to http://walmart.cardcash.com and input your information. The Wal-Mart eGift cards should be emailed to you within an hour.