Bruce Greenwald

Investor, professor, and author described as “one of Buffett’s greatest influences.” Best known for Competition Demystified, which Rick Zullo calls “may be the best business book of all time.”

Greenwald’s framework for competitive advantage centers on captivity: if you have power over the customer or over a resource that enables above-market returns, you have captivity. He breaks it into two forms: Customer Captivity (loyalty, habit, search costs) and Resource Captivity (proprietary access to inputs, technology, or talent). The key insight Rick Zullo draws from him: “moats are the result of competitive advantage, not what creates it — capabilities create them.” A company doesn’t build a moat directly; it builds capabilities that yield captivity that, in turn, yields measurable competitive advantage.

Where this appears

• 1. “Moats” Are a Term… (tweet) — Rick Zullo uses Greenwald’s captivity framework as the bedrock of a simplified moat-building model for startups.