How does YC make money from any of this? /confused Except may be it encourages his startups to move to the Valley, which increases the chances of YC's(and the

How does YC make money from any of this? /confused Except may be it encourages his startups to move to the Valley, which increases the chances of YC's(and the startup's) success. Of course that just validates his essay that the Valley is the place to do startups.