[Ennui.]

It depends how you use them. It's easy to get yourself into debt using them if you don't watch your spending because you may end up overspending and not have the money to pay it off when the bill comes. If used responsibly they're a good way to build credit. The one I have can only be used at a medical provider that accepts it. I've used it for my wisdom tooth removal and general dental checkups because I don't have dental insurance and needed the work done. I've also used them to buy glasses for my parents and I. So I use my card for the important things.