When Facebook entered the mobile payments field in 2014, the service was a hotbed of competition between web companies, and between operators and over-the-top providers. Since then, much of the gloss has come off m-payments. They may be a way of life, thanks to NFC and ubiquitous use of smartphones, but monetizing them has proved challenging in developed markets, especially for MNOs. Undeterred, Facebook is extending its services outside the US and allowing people to exchange money via its Messenger app, starting this week in the UK. “In the US, most people use payments in Messenger to send less than $50 at a time,” David Marcus, head of Messenger, said in a statement. Facebook does not charge for the capability,…