User testing is the key to learn why some customers might never come to use your service.
I am not used to such a concept, so it made me feel uncomfortable, which could indicate that other people will probably not use it so much as well. (still an assumption)
But guess what, there was no such thing in #czechrepublic , even though on the website and the app I used, it says it is possible.
I wonder if this inconsistency hurts the brand? I visited the branch with a promise that was never fulfilled. On the positive note, the refill was less than 1 euro so it seems like a good deal. But it makes me wonder if some people would not return because of this misleading promise.
The moral is when you establish a business and build franchises, try to establish a single vision for all the branches to reduce the chances a customer might not be satisfied.