I swipe the plastic because it's convenient. I NEVER run a balance. I pay it off when the bill comes in. I've haven't paid interest on a credit card in 37 years. It's the same as cash except I don't have to carry the cash. I carry enough money to take care of emergency towing or whatever, but never more than 300 or 400 dollars, unless I'm going somewhere like my annual fishing trip to Canada where they want cash. Then I'll take a couple thousand.