There is a good documentary about how SV came about called, "A Secret History of Silicon Valley", its available online to watch. (http://youtu.be/ZTC_RxWN_xo ht

There is a good documentary about how SV came about called, "A Secret History of Silicon Valley", its available online to watch. (http://youtu.be/ZTC_RxWN_xo http://youtu.be/ZTC_RxWN_xo) In my opinion it is a combination of the people are here along with the location, weather and honestly Stanford. I also think there is a feedback loop. As more people come to SV it makes it a more attractive place which in turn brings more people.