In Kenya, for instance, 68% of phone users make/receive payments on their phone. And 76% of them use their phones for social networking. At the same time, 82% of Kenyans have a mobile phone. But only 59% have access to clean water. -> http://water.org/country/kenya/
So that's .82*.76 = 62% of Kenyans with social networking vs. only 59% with clean water.
But if you google for pay by sms, you'll see there are A LOT of services for that.
Also here's an article with some statistics: http://www.pewglobal.org/2014/02/13/emerging-nations-embrace...
In Kenya, for instance, 68% of phone users make/receive payments on their phone. And 76% of them use their phones for social networking. At the same time, 82% of Kenyans have a mobile phone. But only 59% have access to clean water. -> http://water.org/country/kenya/
So that's .82*.76 = 62% of Kenyans with social networking vs. only 59% with clean water.