But if you already accept Girocard marginal cost of accepting Visa/MC (with which they are co-branded frequently, as I understand) should be extremely low. But what I encountered is a lot of cash-only places, from fast food & restaurants to museums. In US, where I live, I know maybe one or two cash-only restaurant out of a thousand. In Berlin, it felt like the majority is. And the delta in fees can't be that big...