Yep, not long ago the girlfriend spent about 3 hours in Cosco shopping. Got to register; they rang her up and she went to pay. They did not accept her type of card. Discover, I think? She came home w/o groceries!!I carry some cash, not a ton but enough for just in case.
Case in point, went to Walmart and did the self check out thing. About half way through and the readout says "electronic payment out of service, cash only" I wanted what I was buying and the total was 30 bucks and change so I had 2 20's and fed them to the machine and got my change back and brought my items home.
I would have had to walk away if I didn't have some cash on me. I prefer using my debit card but sometimes you have to fall back. Same reason I carry my get home bag in my car and always have extra ammo for my EDC handy.