The "76000 millionaires" number might be a little misleading. I've lived in Silicon Valley since I was 3. I bet that a lot of those millionaires are home owners on the Peninsula who have nothing to do with "Silicon Valley" as we commonly refer to it (the tech industry). My Grandpa, for example, was a high school teacher all his life. He bought a home up in the Burlingame hills back in the 60s or 70s, and that thing is probably worth multi-millions now.