This document discusses factors that determine whether innovating firms or followers benefit more from innovations. It provides the example of EMI, which developed the first CAT scanner but lost market leadership within 6 years as followers modified and improved the design. The key factors discussed are the appropriability regime, the emergence of a dominant design, and ownership of complementary assets needed for commercialization. In a weak appropriability regime, innovators must closely monitor the market and be prepared to modify their design before a dominant one emerges to maintain competitive advantage over followers.