In my 25 years as a technology entrepreneur I was lucky to have three extraordinary mentors, each brilliant in his own field: Ben Wegbreit who taught me how to think, Gordon Bell who taught me what to think about, and Allen Michaels who showed me how to turn thinking into direct and immediate action.

I was also extremely fortunate to be working in Silicon Valley when three of its most influential marketing practitioners and strategists were active. As a VP of Marketing I was strongly influenced by the customer-centric books of Bill Davidow, former VP of Marketing of Intel and founder of Mohr, Davidow Ventures, and consider myself fortunate to have had him on my board at MIPS Computers. Regis McKenna was already a PR and marketing legend with his own firm when I started my career, but his thinking and practice still resonate in my work. Finally, I still remember the hair rising on the back of my neck when I first read Geoff Moore and the notion of a “chasm.” It was the first time I realized there were repeatable patterns of business behavior that could explain the heretofore unexplainable.

At U.C. Berkeley Haas Business School, Jerry Engel, director of the Lester Center on Entrepreneurship, was courageous enough to give me a forum to test and teach the Customer Development Methodology to hundreds of unsuspecting students. Professor John Freeman at Haas has offered valuable insight on the different sales cycles by Market Type. Finally my first teaching partner at Haas, Rob Majteles, ensured that my students got my enthusiasm, as well as a coherent syllabus and their papers graded and back on time. At Stanford, Tom Byers, Kathy Eisenhardt and Tina Seelig were gracious enough to invite me to teach with them in the Graduate School of Engineering and hone my methodology as they offered additional insights on new product selling cycles. Finally, Murray Low at Columbia School of Business allowed me to inflict the course and this text on their students in their MBA program.

In the venture capital world in addition to funding some of my startups, Jon Feiber at MDV and Katherine Gould at Foundation Capital have acted as stalwart sounding boards and supporters.

My friends Steve Weinstein, Bob Dorf, Bernard Fraenkel, and Jim Wickett have made innumerable and valuable comments and suggestions.

Will Harvey and Eric Ries of IMVU were the first corporate guinea pigs to implement some or all of the Customer Development Methodology. This book was required reading for every new hire at their company. Fred Durham at CafePress allowed me to sit on his board and watch a world-class entrepreneur at work.

Besides running engineering at IMVU Eric Ries also moonlighted as copyeditor and helped eliminate the embarrassing typos of the first and second revisions.

This book would be much poorer without all of their contributions.

Finally, my wife Alison Elliott not only put up with my obsession with finding a methodology for early stage Customer Development, and my passion for teaching it, she added her wise counsel, insight and clarity to my thinking. This book would not have happened without her.