In Canada we've had contactless card readers for a few years now - the mobile payments are compatible with the exact same protocol, so instead of tapping your card you just tap your phone.

I haven't even gotten any funny looks tapping my phone with Android Pay at places not advertising it - even just after it came out in Canada.

It's becoming very common outside the US. I think a large part of it is that credit cards are less common in most other countries, especially among young people. Mobile payments have a big advantage in convenience over cash, which is the primary alternative for many people.

Practically everywhere in the UK for example.

Moscow and other big cities in Russia

Literally every western country that isn't the US.