This chapter explains the concept of the momentum flywheel, which is a common aspect of good-to-great companies. A flywheel relies on persistence, which then turns gradually into momentum. Through the simplicity of its motion, the flywheel generates the movement necessary to accelerate to what Collins calls “breakthrough.” To the outside observer, company transformations therefore often appear as if they happen suddenly and dramatically, whereas those on the inside of the company understand and appreciate the persistent efforts required to actualize the breakthrough. There are no miraculous, one-time events for good-to-great companies, but rather years of consistency in accordance with the concepts Collins has already articulated.

By contrast, Collins’s comparison companies often got stuck in what he calls the “doom loop,” spinning around fruitlessly without moving forward towards greatness. Many of them tried to sidestep the process of the flywheel, skipping the buildup process altogether in favor of immediate, dramatic change. Specifically, comparison companies often tried to skip buildup with acquisitions, which generally turned out to be misguided. Good-to-great companies also got involved in acquisitions, but the key difference was in timing; good-to-great companies waited and acquired after the momentum flywheel had already led them into breakthrough.