In business, the lean start-up movement is turning the traditional approach to innovation on its head. Rather than developing an elaborate plan, raising money to fund it, and then following it to its uncertain conclusion; a process that can take years; entrepreneurs in companies new and old are launching small inexpensive initiatives to test ideas, quickly learning from failures and successes, and using that data to further refine the ideas and test them again. Social entrepreneur Michel Gelobter says there's no reason the social sector can't do the same. Gelobter goes through the lean startup process step by step, showing exactly how nonprofits and advocacy organizations can adapt it to increase their impact. He uses dozens of real-world examples: a homelessness group that discovered the one metric they needed to improve to get more people off the streets; a technology-based literacy startup that was able to reach two million children in two years, when it took a more traditionally-oriented program fifteen; and many others. From the glimmer of an idea to make the world a better place to deep reform in the heart of the world's largest government and non-profit bureaucracies, Michel Gelobter shows how the lean start-up can drive a revolution in policy and social change. In business, the lean start-up movement is turning the traditional approach to innovation on its head. Rather than developing an elaborate plan, raising money to fund it, and then following it to its uncertain conclusion; a process that can take years; entrepreneurs in companies new and old are launching small inexpensive initiatives to test ideas, quickly learning from failures and successes, and using that data to further refine the ideas and test them again. Social entrepreneur Michel Gelobter says there's no reason the social sector can't do the same.