Book excerpt: For years, the lean startup has been revolutionizing both new and established businesses. In this eye-opening book, serial social entrepreneur Michel Gelobter shows how it can do the same for nonprofits. Traditionally, whether creating a new business or a new program, entrepreneurs in all sectors develop a plan, find money to fund it, and pursue it to its conclusion. The problem is, over time conditions can change drastically—but you're locked into your plan. The lean startup is all about agility and flexibility. Its mantra is “build, measure, learn”: create small experimental initiatives, quickly get real-world feedback on them, and use that data to expand what works and discard what doesn't. Using dozens of social sector examples, Gelobter walks you through the process. The standard approach wastes time and money. The lean startup will help your organization vastly increase the good it does.