These are the 575 million individuals in mostly emerging markets who lack access to basic financial services, even a bank account.

In principal, the advocates are correct. The time it takes to process a bitcoin transaction — about 10 minutes — is far faster than the three days it would take in the regular banking system. It's also usually cheaper. 

But a new survey from trade association GSM shows that even the most promising emerging-market electronic payments technology, mobile money, has only just begun to break out, meaning it could take years to unseat cash as the payment method of choice in the developing world.

Mobile money can be used for just about anything. You can buy stuff at a grocery store. You can send and receive money to and from friends and relatives. You can pay and tip your taxi driver. And you can buy phone minutes. To upload or withdraw cash, you need only walk to a mobile money agent.