2. Sell unused gift cards: In 2015, an estimated $973 million in gift cards went unused, according to research and advisory firm CEB TowerGroup. Most online gift card exchanges take a few days because you have to mail the card and then wait for a check or direct deposit, but Cardpool kiosks offer instant cash for cards valued at $20 or more. You’ll get slightly less there; the company pays up to 85% of the card’s value at its kiosks, while it pays up to 92% if you sell through its website.