Economics of Gifting.
“Last year, more than $8,000,000,000 was wasted on these [gift certificates]. Not in the value spent, but in fees and breakage. When you give a card, if it doesn’t get used, someone ends up keeping your money, and it’s not the recipient. People spent more than eight billion dollars for nothing… buying a product that isn’t as good as cash.”
http://sethgodin.typepad.com/seths_blog/2007/11/the-8-billion-s.html