In this report Ignacio Mas and Mike McCaffrey document the variety of ways in which digital financial service providers in developing countries have assembled and managed networks of retail stores as their agents for cash in/cash out payments and for account and product sales. They use seven case studies to illustrate how optimal channel structures differ and develop in changing markets in order to meet the strategic objectives of diverse institutions. This paper aims to help providers understand the strategic considerations involved in the design of an agent network and the different models that are currently being used in the market. It also demonstrates the dynamic nature of agent networks, and illustrates how others have augmented them over time.