> Maybe it's the American in me, but I have almost no use for a payment mechanism in my messenger, I have too many. Venmo, Cash, Apple's thing, Google Wallet, whatever -- these all provide everything I need when I need to send money to people.

Don't forget Zelle, which is similar to Venmo but is already built into the apps and websites of a large number of US banks. It's owned indirectly by Bank of America, BB&T, Capital One, JPMorgan Chase, PNC Bank, U.S. Bank, and Wells Fargo. Other major banks, including Chase and Citi, also include it.

That means that a very large number of Americans can do quick and easy US to US payments by phone number of email just using their normal banking apps and sites.