I think it works against them so much. I barely use mine because I can't use it at many small shops, can't use it abroad (because it's ~2% exchange fee), and of

I think it works against them so much. I barely use mine because I can't use it at many small shops, can't use it abroad (because it's ~2% exchange fee), and often buy flights in other currencies to save so can't use it for those (big purchases).