Should be noted that M-Pesa wasn't a brilliant idea, it was the formalization of an already existing behavior in the market. That behavior was to pay for small things (like a drink at a bar) with cellphone minutes because cellphone minutes had an established value and were easily transferable between people. People were doing this already before M-Pesa.
That's actually true of almost every good business -- there is always a worse version already available, even if only through the "abuse" of an existing system.
I'm not Kenyan, but South African, but have been to Kenya to look at mobile payments there. Are you sure about this?
My understanding was that M-Pesa started as a domestic remittance solution. Kenya doesn't have a well developed ATM network, so there was a great need for simple and secure domestic remittances (send money home to your family every week type use-cases).
The remittance solution replaced existing methods like sending physical cash with an "agent" (e.g. taxi driver) at high cost/risk or driving/walking very far to a bank branch.
Once the remittance use-case was established, payments was an easy addition, as there was already value flowing through the system.
Perhaps you mean to say that the "brilliant idea" was to make cellphone minutes easily transferable. This had to have happened for the first time somewhere, and it certainly wasn't in USA.
