It’s really quite simple; Silicon Valley is maybe the one place in which I have ever found nearly everyone I meet has a “pay it forward” attitude. It is infectious, and it means that as a “no name” startup founder, you have nearly infinite access to advice and capital, as long as you are convincing enough and tell a good story. There is no immediate expectation of return. I spent most of my life living in NYC, and I originally started Tinfoil in Boston (and went to school at MIT). Both cities are “startup hubs,” but the same attitude doesn’t exist. Boston was particularly bad about “what’s in it for me?” being the common theme of any conversation.
The upshot is that now I volunteer my time often, and for free, to help others who are just starting out. I cannot predict who will be the next Google, but I enjoy helping smart founders, and I enjoy giving back in the same way I was given to.
A few relevant essays:
http://www.paulgraham.com/siliconvalley.html
http://www.paulgraham.com/ronco.html