Mobile money platforms are networked systems, and understanding key mobile money users is essential for mobile money providers, policy makers, and promoters of financial inclusion who seek to impact their future development. Are there especially active mobile money users with an outsize effect on the system? If so, who are these key mobile money users, what drives them to use the service extensively, and what is the nature of their influence? This report identifies this key user group and explores how the small group of very active users exerts substantial influence over system as a whole.