Very, very early stage companies should SEO their content and page structure as part of their initial product build.
I have managed two companies where we went through painful product restructurings for SEO purposes, but I never realized that, as Josh from Reprise put it, “Hire us at the beginning and you won’t need the services down the road.”
Entrepreneurs have two choices. Suck it up and self educate on blogs like Search Engine Land. Or hire a firm and get quality professional advice. Whatever you do, don’t think you know how to do this because you don’t. SEO firms don’t know how to build killer startups and you don’t know how to optimize for Google. You know how you’re happy you have a good law firm and good investors? Well guess what?
You need good SEO advice too. Get creative and get some help.