Competition between ecosystems is a natural part of competition in the digital network industry. Whether this competition is healthy depends on the number of different ecosystem operators and the sizes of their ecosystems. This chapter explains that there are different stages of ecosystem competition that can be identified. In stage 1 ecosystem competition, firms compete to capture a platform market. These firms do not yet have a vast ecosystem of products and must compete intensely to capture an userbase. The winner that captures the platform market can enter into stage 2 ecosystem competition, where it expands across markets to solidify its position. Once an ecosystem is sufficiently large it enters into stage 3 ecosystem competition; maturity. Here, the ecosystem operator can start to extract profits. When ecosystems grow too large, they become stage 4 incumbent ecosystems. They no longer experience competitive pressures and become able to abuse their ecosystem power to extract excessive rents.