Years ago the line between nonprofit and for-profit enterprises was clear, but that has changed. Nonprofits now offer products that compete with those of the best for-profits, and profits can deliver as much social value as charities. Despite the blurred distinction, all mission-driven start-ups will eventually face a stark choice about which legal structure to adopt, and they need to make it carefully, because it’s hard to undo, say the authors, the CEO of a nonprofit accelerator and a partner in an impact investing fund. To guide their decision, social entrepreneurs should examine several questions: Is the market ready for a for-profit solution. Where is the available capital And which structure would help the organization attract the talent and resources that it requires. Many nonprofits now provide products or services that compete with those of the best for-profit companies. Entrepreneurs must assess the type of talent they need and whether their mission is compelling enough to attract passionate people at below market salaries. We think that a disciplined approach to making those choices as early as possible will serve founders well.