Do you in your startup/website/company do SEO?
Maybe I am just too much of a SEO fanboy (?) but I 'm not sure if startups focus on organic search.
If so, what are your strategies? Like link building, articles, directories (no need to share your top secrets unless you want to :) )
SEO is just a single internet marketing tactic and in all honesty until you have something worth marketing beyond friends and family, I wouldn't worry about it or any of the other internet marketing tactics you might consider until the appropriate time.
With that said there is nothing wrong with creating an SEO frinedly site and blog early on. However I wouldn't get overly concerned about them until you really have something worth marketing. At that point you need to look at the marketing plan and I would be sure to include SEO as part of it.
SEO really has three key parts. Good on page optimization, quality content creation, and high quality link building with solid anchor text. Do those three things well and you will succeed.
I hope that helps.
The the question that I think you might be trying to ask is "whether all startups go into the grey and black-hat areas of SEO". The obvious answer to this is no. Lots do though.
You can do link building passively (review posts, guest blog posts etc...).
I do agree with some others that it would be unwise not to do a little leg work from the beginning when building your site.