One of the biggest challenges in rolling out mobile financial services is the establishment and the effectiveness of the agent network. Agents are the touch-points where the subscribers of the service can get money into and out of the system. (Agents are often also referred to as cash-in and cash-out points).In instances where a subscriber arrives at an agent with the need to withdraw a large amount it does happen that the agent do not have enough cash to satisfy the cash-out request. This leads to frustration and is one of the reasons why take-up of these systems are slower than what is expected. This problem is referred to as the agent liquidity problem - how to ensure that the agent has sufficient cash available to satisfy the need of the system.
This problem is often approached in a way where the system keeps track of the actual cash available in the drawer of each agent in order to guide subscribers where they can withdraw big amounts. This approach is overtly complex and often fail because of the informal nature of agents businesses. I have recently seen a system that works on averages (what is the average pay-out at an agent or in a town etc.). The system also calculate deviations from real-time on the basis of the amount. For instance, if you want to withdraw $100 you will be able to do so in six hours. This enables the agent to collect sufficient cash if they are pre-warned about a pending withdrawal.
It is plans and innovations like this, that will help deliver financial services to the poor.