Many people—including us—have noted that retailers need to manage the transition that occurs as they mature and high-revenue growth slows to single digits. But what has not been fully appreciated is that retailers progress through three stages in their life cycle: 1) a phase in which adding physical stores remains profitable, 2) one in which the store network is largely built out but revenues can still grow through online expansion, and 3) a phase in which revenue growth opportunities are limited, leaving cost reduction as the primary lever to increase profits.