I believe he means that revenue needs to come before you seek VC funding, in essence, he feels bootstrapping is a more sustainable business model. Though it doesn't have the glitz and glamour of YC or a large bank account, Dan is bright enough to realize that this funding climate won't always exist. If he figures out how to bootstrap effectively, VC funding is that much easier in the present, and he can keep going in the future when there aren't so many angels out there throwing down fairy dust from Sand Hill Road.