[bbc] Millions of Africans are using mobile phones to pay bills, move cash and buy basic everyday items. So why has a form of banking that has proved a dead duck in the West been such a hit across the continent?
It has been estimated that there are a billion people around the world who lack a bank account but own a mobile.
Africa has the fastest-growing mobile phone market in the world and most of the operators are local firms.
In countries like South Africa, for example, mobile phones outnumber fixed lines by eight to one.
In Kenya there were just 15,000 handsets in use a decade ago. Now that number tops 15 million.
Setting up a bank account on your phone is straightforward. All you do is register with an approved agent, provide your phone, along with an ID card, and then deposit some cash onto your account.
You can use it to pay for everything from beer to cattle - one Masai farmer told the BBC that when he sells cows in Nairobi, he puts the money on his phone to ensure that robbers can't get his cash.
A Kenyan woman said she uses the technology to transfer money from her phone to that of her parents while a Nairobi businessman told us it was handy for settling customer accounts.
Africa's mobile banking revolution