Signal Adds Cryptocurrency Support
Payments in chat is inevitable.  I think that eventually all chat will have convenient payments or people will stop using it.  Of course that doesn't necessarily mean cryptocurrencies, but until the large financial companies get involved (and they are notoriously risk averse), cryptocurrencies are a natural way to do this.As well as secure chat already needing much of the same key management infrastructure that cryptocurrencies need, it also hooks you into social networks - so  you could have key recovery schemes where you trust a number of friends to hold portions of your backup keys (somewhat like what you probably do with your real life house keys).Trust, money and communication are all network phenomena, and using the same fabric for them all makes a lot of sense.