This is an in-depth study on how Small Area Estimation poverty can be used to promote change and improve the quality of life for poor people. It presents the experiences of 12 countries, illustrating a wide range of impacts that poverty maps can have on policy making, such as target programmes and resources, opening new dialogues on poverty, adjusting existing systems, tailoring programmes to local conditions, strengthening accountability, and promoting evidence-based decision making. This publication also outlines the processes of creating these maps and looks at how they are used and how the impact of these maps can be increased.