"CHICAGO (Reuters) - U.S. retailers wished for mountains of plastic gift cards on Friday as they kicked off their annual after-Christmas blitz, the last chance to salvage a disappointing holiday season.

For the second year in a row, Christmas demand failed to live up to expectations, particularly at discount and lower-priced department stores. But unlike last year, luxury chains appeared to be thriving, helped by a recovering U.S. economy and stock market.

Retailers blamed the disappointing sales on a myriad of factors including bad weather, a heightened security alert and the popularity of plastic gift cards.

The gift cards are not recorded as revenue until they are redeemed for merchandise, so retailers are hoping that people spend them fast enough to count toward December sales."