Steve Blank, Creator of Customer Development

“This is a must read for all startups and their stakeholders.”

Steve Blank, creator of Customer Development, author of The 4 Steps to the Epiphany

Eric Ries, Creator of the Lean Startup

“The Entrepreneur’s Guide is an easy read. It is written in a conversational tone, doesn’t take itself too seriously, and avoids extraneous fluff.”

Eric Ries, creator of The Lean Startup® framework, author of The Lean Startup

Hiten Shah of KISSmetrics

“Any and every startup founder needs to do Customer Development. No startup founder should be without this book.”

Hiten Shah, Founder of KISSmetrics

Salim Virani, founder of

“A great job of making Customer Development process and jargon easily understandable. This is for entrepreneurs who are too busy to geek out on Lean, but want to dig deeper into what Customer Development can do for them. A great starter and companion to Four Steps.”

Salim Virani, Creator of

“Quickest & best way to get your head around Customer Development. Read this first and then read The Four Steps to the Epiphany. ”

Noah Kagan, Founder of AppSumo

Edwin Oh

“A great little book whose brevity and clarity shine a laser-like focus on the core concepts of Customer Discovery. Should be required reading for every entrepreneur (and is in my class at Stanford)!”

Edwin Oh, Stanford University instructor, founder of Infrastructure Group

Tor Grønsund

“Small but big. This handbook rocks. A must-read for aspiring entrepreneurs.”

Tor Grønsund, Founder of Lingo & Lecturer of Entrepreneurship at University of Oslo

Steve Cheney

“Why haven't you read the #CustDev book yet? ”

Steve Cheney, VP of Business Development - GroupMe, TechCrunch contributor

Waverly Deutsch

“The Entepreneur's Guide to Customer Development is required text for our MBA students at the University of Chicago Booth School. ”

Waverly Deutsch, Clinical Professor of Entrepreneurship, University of Chicago Booth School of Business

“Get this book to learn how to get your customers to help you build a product that they will use and pay for. ”

Rob Fan, founder and cto of sharethrough

Willie Belk

“It's the first book I've seen that creates a practical framework for applying customer development. Product developers at all stages of growth are lucky to benefit from Patrick and Brant's work.”

William Belk, Head of Product for Beachmint


“Patrick has a true passion for bringing practical wisdom to entrepreneurs, and aspiring entrepreneurs. His approach is unpretentious, and makes the often overwhelming detail in Customer Development more approachable and clear.”

Ravi Belani, seed investor, formerly part of teams at DFJ, McKinsey, Zaplet

“Get the CustDev book to dive deep into customer interviews and understand how your product can be developed to meet your customers' needs.”

Dan Martell, founder of Flowtown, angel investor

“Fantastic book. Melds perfectly with design, UX & UI.”

Janice Fraser, founder & ceo, LUXr

“This book is filled with great, practical advice in a simple-to-comprehend format. It will take you from zero to Customer Development in under an hour.”

Brett Durrett, VP Eng & Ops at IMVU

“Powerful book in a small package. It will change your startup. ”

Ryan Fujiu, Head of Product & Partnerships for

Joe Zulli

“The CustDev book changed our culture of product development at”

Joe Zulli, cto at

Dave Binetti

“A crash-course in Customer Development and "Getting out of the building". Buy it today. ”

Dave Binetti, Co-Founder of Votizen Authentic Voter Network

Trevor Owens

“Before you can participate in a Lean Startup Machine event, you get a copy of the CustDev book. ”

Trevor Owens, founder & ceo, Lean Startup Machine

“Love it! Required reading for all NYU entrepreneurs.”

Frank Rimalovski, managing director of NYU Innovation Venture Fund

“I recommend it. ”

Kevin Taylor, Director of Talent Development at Groupon, DePaul University instructor

Tom Eisenmann

“This book is conceptual and practical at the same time: a powerful combination!”

Tom Eisenmann, Howard H. Stevenson, Professor of Business Administration at Harvard Business School; Chair MBA Elective Curriculum

Patrick Foley

“I always recommend The Entrepreneur's Guide to Customer Development. ”

Patrick Foley, ISV Architect Evangelist for Microsoft

David Chapman of UCL

“Our UCL (University College London) students love The Entrepreneur's Guide to Customer Development. Thanks to Brant & Patrick for writing this helpful book. ”

Dave Chapman, Deputy Head of the Department of Management Science and Innovation at UCL (University College London)

Enrique Allen

“All of our 500 Startups companies get a copy!”

Enrique Allen, 500 Startups, The Designer Fund

Emily Chan

“The Entrepreneur's Guide to Customer Development has transformed the UCSB Eco-Entrepreneurship program. It teaches our students critical startup concepts and key questions to ask through the customer discovery process.”

Emily Chan, visiting lecturer/advisor in eco-entrepreneurship at UCSB Bren School

“I recommend The Entrepreneur's Guide to Customer Development to all of our clients. If you buy it and don't think you got your money's worth I'll personally send you a refund.”

Parker Thompson, Director of Business Development at Pivotal Labs

“New customer development ebook rocks... check out "Am I making a product somebody needs?"

Andrew Chen, entrepreneur, blogger, former venture capitalist

Rich Collins

“Simply the best way to introduce your team to Customer Development.”

Rich Collins, Founder of Lean Startup Circle, Mac developer

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