"At the core of the Lean Methodology is the scientific method: Creating hypotheses, running experiments, gathering data, extracting insight and validation or modification of the hypothesis. A/B testing is the gold standard of creating verifiable and repeatable experiments, and this book is its definitive text" -- Steve Blank, Adjunct professor at Stanford University, co-founded of multiple startups, father of modern entrepreneurship, author of The Startup Owner's Manual and The Four Steps to the Epiphany

"This book is a great resource for executives, leaders, researchers or engineers looking to use online controlled experiments to optimize product features, project efficiency or revenue. I know firsthand the impact that Ronny's work had on Bing and Microsoft, and I'm excited that these learnings can now reach a wider audience" -- Harry Shum, Executive Vice President, Microsoft Artificial Intelligence and Research Group

"A great book that is both rigorous and accessible. Readers will learn how to bring trustworthy controlled experiments, which have revolutionized internet product development, to their organizations" -- Adam D'Angelo, Co-founder and CEO of Quora and prior CTO of Facebook

"This book is a great overview of how several companies use online experimentation and A/B testing to improve their products. Kohavi, Tang and Xu have a wealth of experience and excellent advice to convey, so the book has lots of practical real world examples and lessons learned over many years of the application of these techniques at scale." -- Jeff Dean, Google Senior Fellow, and SVP, Google Research

"The secret sauce for a successful online business is experimentation. But it is a secret no longer. Here three masters of the art describe the ABCs of A/B testing so that you too can continuously improve your online services." -- Hal Varian, Chief Economist, Google, and author of Intermediate Microeconomics: A Modern Approach

"Do you want your organization to make consistently better decisions? This is the new bible of how to get from data to decisions in the digital age. Reading this book is like sitting in meetings inside Amazon, Google, LinkedIn, Microsoft. The authors expose for the first time the way the world's most successful companies make decisions. Beyond the admonitions and anecdotes of normal business books, this book shows what to do and how to do it well. It's the how-to manual for decision-making in the digital world, with dedicated sections written for business leaders, engineers, and data analysts" -- Scott Cook, Intuit Co-founder & Chairman of the executive committee