I have never met the man, heard him talk in person or even attended a one of his many speaking events (that I know of) – though we have worked in the same industry and the same market.
Oddly, I read his book for all of the intangibles not noted in the title, namely his sense of where business and design overlap and influence each other.
Even more oddly, I avoided reading the book because of its title. The word sketch was an indicator of something aside my interests. Curiously, his take on sketching was a powerful take away, where all of the other stuff seemed common sense based on my years of experience.
I have learned the lesson of sketch many times in my career. At several intervals, while short on time, running out of budget, or overly confident… I have jumped to the computer to execute a design I was certain I had worked out. Always to frustration and sometimes failure. It is even a syndrome to which I frequently talk to young designers and students. Always sketch your ideas first. But for some reason I was never able to fully articulate why. Bill takes care to explain the malleable and unfinished qualities of a sketch that hit me over the head like a ton of bricks. That lack of finality has great value. It lets designers and others have a glimpse into your idea, and yet interpret those ‘yet to be determined’ attributes. It allows people to feel free to input, add to the idea, and take it in new directions. The lack of detail and finality actually serve the designer to great benefit.
I now read pretty much everything he writes as it comes along. I look forward to hearing him speak sometime very soon.