Lots of lower income areas have places (some of which are legit, most of them not) that will purchase gift cards for 50 cents on the dollar or less. The idea is that someone might gift you a giftcard to, say, Home Depot, but you need food rather than lumber. So you sell the gift card to a broker at a steep discount and pocket the money.

But this also a good way to launder money, most often for low-level drug transactions. Drug addicts steal credit cards or pass bad checks to buy gift cards. Then either give the cards to a dealer directly, or to a broker. The broker gives them cash, which they take to the dealer.