Ecosystems are increasingly popular, fueled by the success of iconic examples such as Google, Apple, Facebook, and Amazon. Yet confusion about them abounds, and many commonly held beliefs about ecosystems simply aren’t true. To objectively analyze several key details about ecosystems — such as how often they succeed, how important it is to be first, and how long they take to pay off — we conducted a quantitative study of ecosystems over the past four decades. The results show that ecosystems tend to follow one of four paths during their life cycle. Moreover, there are three critical windows during which actions by management can have a disproportionate effect on long-term success.