Most stores here issue a so-to-speak 'point card' if we wish. One point per a 100 yen purchase, something like that. It is recorded and is subject to a discount or something at some point. I think that kind of service is found anywhere in the world. I don't think it is called 'point card' in English-speaking countries. Reward Card? Or any other?
Thank you very much, todol, for the valuable terms as always.