I guess it depends what you are optimizing for. Groceries is a quite big expense part for me, so REWE, Aldi and tegut in Germany are quite good for earning. Ot

I guess it depends what you are optimizing for. Groceries is a quite big expense part for me, so REWE, Aldi and tegut in Germany are quite good for earning. Other expenses are traveling, where basically everyone accepts Amex. Starbucks accepts is as well, quite a lot of McDonalds and most fashion retailers as well. You probably can't survive on Amex alone, but at least in Germany there is a quite big chunk that you can cover.