Absolutely nothing (other than the scale of the challenge). Google doesn’t care whether you’re a startup, a major financial institution or the smallest online retailer – all it cares about is connecting people with the most relevant content for each search query. The SEO requirements for a startup are exactly the same as the world’s biggest brands and search engines want to see the same things from you as any other kind of business.
This topic seems actually quite controversial. Google answered the question by what could be taken as a denial. But their answer was kind of open to interpretations. And on the other hand, there are studies (one of them from Moz) that showed linking out has an impact. So, how can you be so assertive? Is it something that comes out from your own experiments?
For a small business, it is better to start with Organic SEO because aside from it is a low-cost investment, it will build your internet presence gradually and eventually have a solid foundation in your own niche – provided that you are doing the right way. It is not bad to invest in non-organic. You just have to make sure that you are investing on the right campaigns and not on the overly artificial ways to gain traffic and rank. Avoid investing too much on paid advertising and instead invest on creating relevant and useful content.
The term “organic traffic” is used for referring to the visitors that land on your website as a result of unpaid (“organic”) search results. Organic traffic is the opposite of paid traffic, which defines the visits generated by paid ads. Visitors who are considered organic find your website after using a search engine like Google or Bing, so they are not “referred” by any other website.