M-PESA, the world-leading mobile money system has transformed lives and livelihoods in Kenya and beyond. Financial inclusion for the marginalized in emerging markets is now feasible and achievable. Mobile money promises a more scalable and cheaper alternative to the large unbanked populace than conventional banking. In the recent years, Sub-Saharan Africa has rolled out a number of practical technology-driven innovative products leading to more and more cashless transactions. One such product is M-PESA; a mobile-based financial innovation that has achieved unprecedented growth since its inception in March 2007 by the mobile network operator, Safaricom. In spite of its tantalizing potential, one major challenge is how to optimally capture the market. This paper analyses the M-PESA ecosystem, by building theoretical linkages between two main theories; i) Innovation Diffusion Theory and ii) Unified Theory of Acceptance and Use of Technology. The questions the author is addressing are: Which factors are responsible for M-PESA’s rapid adoption? How does Safaricom maintain its strong grip as a Mobile Network Operator in the financial sector.