Based on a ten-year study of some 2,000 technology, service, and product companies in various industries, this work argues that most growth strategies fail because they wrongly diversify from the core business. It identifies and explains three key factors that differentiate successful and unsuccessful growth strategies, and borrows lessons from private equity and start-up ventures to explain how to resolve common problems of expansion. Zook is director of a global business strategy consulting firm. Allen is CEO of a global venture capital firm. c. Book News Inc.