Climate change, income inequality, injustice and other vexing social and environmental challenges are changing our thinking and the way businesses operate. As social media helps good and bad news about business practices travel fast, established for-profit companies are taking corporate responsibility seriously. And increasingly, young and socially aware entrepreneurs are aspiring to set up new ventures that address these problems while making money, and social entrepreneurship has become a rapidly growing field. However, despite the good intentions of social entrepreneurs, it remains challenging to measure how much of a difference they are making. In this article, we provide an overview of social entrepreneurship and show options for capturing its impact-a key part of making the venture sustaining and attracting impact investors who want to channel their money into ventures with strong results.