We have several vending machines scattered throughout the campus. I never carry cash, so, I always use my cards. Today, I tried swiping my Discover giftcard and it worked. I tried to swipe it again and got an error message. So, I pulled out my debit card and got an error message. Next, I pulled out my Chase card and got an error message. I went on to 3 other vending machines and they all wouldn't take a card.
I went all the way to my vehicle to get some change. I only had enough change to buy one thing. Right before I got back to where I was going, I thought about my Discover zip card and if it'd work with the card machine I've never used the zip card before. Low and behold, I waved my phone in front the payment machine and it worked!!! I never been so happy for a card to work. 
I almost never carry cash. I very rarely need to have cash, there are just so many places that take debit or credit. I may have a dollar or two at the bottom of my purse.
Those vending machines that take plastic are the death of me. 
My lack of cash use to work in my favor that I never had change for the vending machines. Within the last month they put a credit swiper in the machines at work and now I find myself grabbing snacks out of those machines at least twice a week.
