I disagree. Obviously, building product is the sine qua non of a startup. But, there's a huge difference for companies that can build a great product, and the

I disagree. Obviously, building product is the sine qua non of a startup. But, there's a huge difference for companies that can build a great product, and then access the YC brand and network, and those that don't have access to that brand and network. There's a number of companies that build a great product, but then they need access to a network for advice and funding. If you're going to get funded via Angel List, for instance, you have to have some form of social proof.