The Lean Startup has a kind of inexorable logic, and Ries' recommendations come as a bracing slap in the face to would-be tech moguls: Test your ideas before you bet the bank on them. Don't listen to what focus groups say; watch what your customers do. Start with a modest offering and build on the aspects of it that prove valuable. Expect to get it wrong, and stay flexible (and solvent) enough to try again and again until you get it right. It's a message that rings true to grizzled startup vets who got burned in the Great Bubble and to young filmgoers who left The Social Network with visions of young Zuckerberg dancing in their heads. It resonates with Web entrepreneurs blessed with worldwide reach and open source code. It's the perfect philosophy for an era of limited resources, when the noun optimism is necessarily preceded by the adjective cautious. -Wired

I make all our managers read The Lean Startup. -Jeffery Immelt, CEO, General Electric

Eric has created a science where previously there was only art. A must read for every serious entrepreneur-and every manager interested in innovation. -Marc Andreessen, co-founder of Andreessen Horowitz, Opsware Inc. and Netscape

This book should be mandatory reading for entrepreneurs, and the same goes for managers who want better entrepreneurial instincts. Ries's book is loaded with fascinating stories-not to mention countless practical principles you'll dearly wish you'd known five years ago. -Dan Heath, co-author of Switch and Made to Stick

Ries shows us how to cut through the fog of uncertainty that surrounds startups. His approach is rigorous; his prescriptions are practical and proven in the field. The Lean Startup will change the way we think about entrepreneurship. As startup success rates improve, it could do more to boost global economic growth than any management book written in years. -Tom Eisenmann, Professor of Entrepreneurship, Harvard Business School

The Lean Startup is the book whose lessons I want every entrepreneur to absorb and apply. I know of no better guide to improve the odds of a startup's success. -Mitchell Kapor, Founder, Lotus Development Corp.

At Asana, we've been lucky to benefit from Eric's advice firsthand; this book will enable him to help many more entrepreneurs answer the tough questions about their business. -Dustin Moskovitz, co-founder of Facebook and Asana

Ries' splendid book is the essential template to understand the crucial leadership challenge of our time: initiating and managing growth! -Warren Bennis, Distinguished Professor of Business, University of Southern California and author of the recently published, Still Surprised: A Memoir of a Life in Leadership.

The Lean Startup isn't just about how to create a more successful entrepreneurial business, it's about what we can learn from those businesses to improve virtually everything we do. I imagine Lean Startup principles applied to government programs, to healthcare, and to solving the world's great problems. It's ultimately an answer to the question 'How can we learn more quickly what works, and discard what doesn't?' - Tim O'Reilly, CEO O'Reilly Media

Eric Ries unravels the mysteries of entrepreneurship and reveals that magic and genius are not the necessary ingredients for success but instead proposes a scientific process that can be learnt and replicated. Whether you are a startup entrepreneur or corporate entrepreneur there are important lessons here for you on your quest toward the new and unknown. -Tim Brown, CEO of IDEO

The roadmap for innovation for the 21st century. The ideas in The Lean Startup will help create the next industrial revolution. -Steve Blank, lecturer, Stanford University, U.C. Berkeley Haas Business School

The key lesson of this book is that start-ups happen in the present-that messy place between the past and the future where nothing happens according to PowerPoint. Ries's 'read and react' approach to this s