Today chat is the king and the growth is incredible. No surprise IRC predates the Web and ICQ came before Google.
So why don't we use chat messages to pay our bill and send money? The protocol should be easy: you receive a request of payment with a chat message and you answer with another chat message including your public key.
Should this the natural evolution for Whatsup, Line, Viber, WeChat and all the other instant messengers?
After all, you have your phone in your pocket more frequently than your credit card in your wallet.