What's the hidden power behind the success of Wikipedia, Craigslist, and Skype? What do eBay and General Electric have in common with the abolitionist and women's rights movements? After five years of research, Ori Brafman and Rod Beckstrom share some unexpected answers and a tapestry of unlikely connections. They argue that organizations fall into two categories: traditional "spiders," which have a rigid hierarchy and top-down leadership, and revolutionary "starfish," which rely on the power of peer relationships.