Swapping That Unwanted Gift Card for Cash

On this day after Christmas, you expect volume to be low – but we know about an exchange that's likely to very, very busy. We're talking about a website where you can exchange unwanted gift cards. CNBC’s Carl Quintanilla revealed all the details on this morning’s “Squawk Box.”

Buy or Sell – that’s what’s top of mind for traders today on the website Swapagift.com

During an interview on "Squawk Box," the site’s president, Michael Kelly, explained how it works.

You can either buy the gift cards outright (they're typically sold at a slight discount) or barter with a gift card that you already have – but don't want.

Kelly said, major home-improvement stores and electronics retailers are more likely to trade closer to face value than specialty retailers. (He's not sure why. It's probably because everyone lives near a Home Depot, he says.)

Kelly also said growth on his website has been explosive – 20% this year. As the number of gift cards issued increases, Kelly says, “The secondary market will increase, too.”