How will mobile financial services achieve mass adoption among both the banked and unbanked?

Utiba (now owned by Amdocs) had an answer to this. Recalling from memory:

Reaching a mass market will be driven by a comprehensive consumer financial inclusion.

In order of priority:

• Telecom Services (Easy To Achieve - Low Hanging Fruit)
• Money Transfer
• Merchant Payments
• Savings
• Credit & Insurance (Difficult to Achieve)

The Length of the arrow above indicates effort and time required to reach the goal.

References:

• Amdocs: Telecommunications | Unified Communications | Network Services | Managed Network Services
• Utiba: Amdocs Mobile Financial Services