The best answers to this question are Content and Social Sharing. Having the right content with the right length, talking about the right things, to the right people all while being great!
Social Sharing consists of creating great unique shareable content that is done in the context of the platform.
When you do these things well, Google and other search engines take notice and move you up the rankings.
You're probably going to hear my answer in one form or another from a couple other people here on Clarity. Working the last couple years in this crazy online marketing business one thing always seems to top the latest shiny object in regards to SEO. Are you ready?
Content and Context.
You have to have the content that people want to see and you have to use that content in the correct context for the online platform you are using.
You still have to have the content that people find helpful or at least fulfills some sort of need for your audience. If you don't have this then why would people help your SEO by sharing your stuff? Make sure your content is worthy of being found by the search engines.
And when it comes to content use the correct content on the platform you are using. This means if you're using YouTube then you better have some great videos. If your on Tumbler and you're not taking advantage of the fact that you can use GIF's you're missing out. Pinterest with horrible photos? Don't bother.
Pay attention to how the platform is displaying content. With Facebook right now you can see them trying to move more toward a visual platform as opposed to text based sharing. With your posts in the past you would just past a link to the page you wanted to share and hit enter. Now, for Facebook, many suggest pasting the link and then when the image preview comes up deleting the link you posted. This leaves a link to the site via a preview image and looks much better and gains more attention when people see it in their news feed.
With SEO you can try to outsmart everyone with the latest schemes to game the system, but content and context always matter. Build your SEO the correct way and then you won't have to worry about the next Google update making your web site disappear.
With a little more detail I could help you out in regards to specific SEO tactics you could use. All you need to is schedule a call so we can chat about your unique situation.
Until then Good Luck!
Don't focus on SEO. Focus on generating articles and videos and commentary that is compelling to read and strikes a nerve in your audience, and simultaneously hang out (post helpful feedback) on blogs and forums with said audience so they can get to know you as a trusted resource.