This isn't terribly surprising:
Shoppers across America have millions of gift cards tucked away in envelopes, drawers and wallets. And some of the nation's largest retailers are profiting as a result.
[. . . ]
Last winter, Best Buy Co. reported a $43 million gain in fiscal 2006 from cards that hadn't been used in two or more years. Limited Brands Inc. recorded $30 million in 2005 revenue because of unredeemed cards.
I hate gift cards, one reason being that I'm one of those who lose track of them. I cleaned a corner table in my living room once and found a card that had expired three months earlier. I have one around the house right now, but for the life of me I can't remember where. A gift card is a way of saying you don't know what to get someone. Cash would be a much better method of expressing that particular sentiment.