Another problem is that paying with your phone is only more convenient if you have your phone in your hand already. Otherwise, men are probably going to the poc

Another problem is that paying with your phone is only more convenient if you have your phone in your hand already. Otherwise, men are probably going to the pockets of their trousers (wallet in one, phone in the other). Women are probably going dig in their purse, which has both their cards (often in a smaller wallet) and their phone. At that point you may as well go for the tried-and-tested, rather than the phone. If you happen to have earbuds in (so many people, these days) and then moving the phone around is annoying because of the cord. If the smart watches can do payments then it should be more convenient, provided the actual mechanics of holding or swiping the back of your wrist to the terminal works.