Do Social Media Likes and Shares Help Your SEO?
According to Google, the answer is no.
Matt Cutts (of Google) said this in a video in Jan of 2014.
John Mueller (also of Google) said this again in in Aug of 2015.
John Mueller and Gary Illyes (both of Google) each tweeted this again in Jun of 2016.
Does this mean that if you're working to improve your SEO you should not spend time with social media?
No. Social media does provide indirect benefits.
Two things that do directly benefit your sites SEO are links to content on your site and comments on your blog posts.
Links were the original "currently" of Google search and I think everyone gets their importance to your SEO.
As for comments, Google tends to rank sites that are updated more often higher than sites that are updated less often. Every blog post comment is an update. When you have conversations start in the comments section of your blog posts you've stumbled across SEO gold.
Where social media comes in is in exposing your content to more eyeballs. Some of these people like your stuff enough to themselves like and/or share it.
And some of these people like your stuff enough to link to it and/or comment upon it.
And that is the indirect benefit social media provides to SEO.