What are the critical success factors in driving a mobile money service to critical mass?

First you need reliable technology with 100% integrity. That has to be the basis of your product, but the critical success factor to get to critical mass is you need a dealer network that is ubiquitous across the country. Once you start signing up customers, if they use the system, then it has a viral marketing effect - you don't really have to advertise as people tell one another. And the system has to work properly - you can't have customers send their money to a remote area, only for the recipient to find there's nowhere to cash their money out.