Though you can buy physical gift cards at Costco warehouses ... can be sent to your mailing address, as can the Starbucks $40 gift card bundle (a multipack of four $10). Why does this matter?

They looked at things like Popularity plus whether or not you have to pay any fees to buy the card. I hate that. Here's what they found. Number 5, *** Starbucks gift card. Number 4, Walmart gift card.