"If even Wal-Mart is unable to have a significant sales increase considering its low prices, it means that the American shopper is truly tapped out," retail analyst Britt Beemer at America's Research Group said, CNNMoney.com reported Thursday.

Sales at Wal-Mart locations in business for a year rose 1.9 percent in December, a sharp reduction from the 2.6 percent gain made in December 2007. Sam's Club sales were not even that robust, rising 0.1 percent, compared with a 1.3 percent gain in December 2007.

Wal-Mart Stores vice chairman Eduardo Castro-Wright said, "the holiday season was more challenging for retailers than expected."

Beemer said he was "shocked and disappointed," by the holiday sales figures.