This book suggests a new approach for explaining the international diffusion of innovations. Based on this new theory an applicable concept of new innovation market entry is presented. The Lead Market Concept suggests that a firm can develop globally successful innovations in concentrating its market research and innovation development activities on the respective lead markets for each innovation. The focus is on three questions: First, what is a lead market? Second, what constitutes a lead market? And third, how can companies harness lead markets to generate global innovations? Considering the international, cross-border diffusion of innovations one can observe that a particular technological design such as the facsimile machine, the personal computer or the mobile cellular telephone is often adopted by one country or region ("lead market") much earlier than by other countries. The study suggests a theo-re-tical explanation for the phenomena of lead markets and collects empirical evidence from a detailed case study of the cellular mobile telephone industry. A new innovation development and market entry concept is presented.