I know zero. In fact, before I saw this post I didn't even know what it was. Now, I'm pretty sure this is because I don't live in the US. Is this a purely US-s

I know zero. In fact, before I saw this post I didn't even know what it was. Now, I'm pretty sure this is because I don't live in the US. Is this a purely US-specific service, or is it available (and used) anywhere else. If not, are there similar services in other countries? I believe Wepay in China is something similar, but I don't know much about that one either.