This book is more or less the must have bible of the lean startup movement. Steve Blank is a serial entrepreneur who after 20+ years doing startups retired and “…moved from being an entrepreneur to teaching entrepreneurship to both undergraduate and graduate students at U.C. Berkeley, Stanford University and the Columbia University/Berkeley Joint Executive MBA program” (his own words).
This book is basically the teaching material he is using for his courses.
The Customer Development process is based on the insight that a startup is fundamentally different from an established company. A startup is in an exploration phase where both the product and the market are unknowns. That is why a startup has to put at least as much focus on developing the customer as on developing the product.
This is in fact true of any organization building something new for an untested market, not just startups.
As the book is more or less a collection of notes the readability could have been better. It’s a fairly dense read but very rewarding. If you’re serious about doing a lean startup this book is a must-read.