Let me be honest with you: I am 31 and this month I got my first credit card. Before that I just asked my wife if she could buy something online if there was any credit card involved. The reason why I am such a late adopter? I am a laggard regarding plastic cash, I like the design principle of physical cash. I like my euro coins and notes. For the simple reason that if I spend everything I see it directly: my wallet will be empty.
That is the main reason I don’t like plastic cash: there is less an easy (visual) overview on how much money you spend (the card has the same color after spending and is still the same size), and it is harder to identify how much money is left and even the value of a cup coffee is becoming more abstract, everything is just on swipe away (and a push on the green ok button).
I might be old fashioned, though I strongly believe a lot of people would be in less financial trouble if they hadn’t had any plastic cash and just plain and simple physical cash. The issue with plastic cash (and with the upcoming NFC on more devices) is design. When designing a different non physical way of doing transactions, try to provide the same insight as we can with physical cash. Wouldn’t it be helpful (both for you as the seller) that your card changes it’s color as soon as a certain limit is reached?
So for me it is about the design of plastic cash, spending 100 euros is similar as spending 2 euros. If we could have somehow some of the characteristics that physical cash has, for example the alerting functionality you are out of cash or that a certain limit is reached, or that paying five euros for a cup of coffee is rather expensive, then I would completely switch to plastic or to NFC.