It's estimated $100 billion in gift cards were purchased this year. However, consumer advocates say that about 2-5 percent of them are never redeemed.
Shoppers acknowledge they're among that group.
"We might not have them on us when we're out, we forget about them," gift card recipient America Alvarado said.
"They're great to receive because you can get whatever you want, but then you forget you have them and you lose them or you just forget," shopper Heidi Wolcott said.
California law specifies that gift cards never expire. So they retain their value until used.
Their value is enhanced right after Christmas when seasonal merchandise is marked down, typically by 50 percent.
"Sometimes I feel very foolish when I've spent all this money, and I say, 'Oh my gosh, I could have used my gift card,'" shopper Patty Horikawa said.
An estimated one-third of gift card purchases exceed the value of the card. But that means two-thirds of the transactions leave residual cash value. At that point, consumers might tuck them away and forget them. By state law, though, any gift card with a balance under $10 can be redeemed for cash.
Consumer experts point out other options.
If you get a card for a store or restaurant you don't patronize, you can sell them for a fee at a number of websites. You can also donate the value of the card.
Some retailers are also issuing gift cards when you purchase certain products, instead of offering a discount. That serves as a way to get you to return to the store and spend more money.
"We're offering gift card with deals during the holidays, so if you're buying, for example, a coffee maker, you get a $5 gift card, you buy an iPod, you get a $25 gift card," Target spokesperson Jay Patel said.
The best tip not to forget using them is to carry them with you when shopping.