Intuitive Surgical, Inc. (ISRG)

Intuitive Surgical sells surgical robots but earns from the instruments consumed in every procedure.

The razor-and-blades model in its purest form. The robot is expensive and sold rarely; its instruments and accessories have limited lives and are bought continuously. The company's headline metric is therefore not systems sold but procedures performed on the installed base.

A hospital that buys a system trains its surgeons on it and builds it into workflows — changing supplier afterwards is extremely expensive. The installed base grows slowly and accumulates, and recurring revenue grows with it, making the business steadier than a conventional equipment maker's.

The risks are competing platforms emerging as key patents expire, and hospital budgets that govern new system purchases. Procedure volume is only loosely tied to the economic cycle: elective interventions are postponed, but not all of them. The company pays no dividend.