This is an interesting case study I read on MOZ, SEO vs. SMM. It’s a little long, so I will try to summarize it and you can click the link if you want to read the whole article.
The question under consideration is: Do blogs that focus on SEO get more traffic from search engines that blogs focused on social media marketing (SSM)? Conversely, do blogs focused on SSM get more traffic from social media than blogs focused on SEO? It seems like a reasonable assumption that a blog operator would get more traffic from a source you are an expert in.
What is actually happening is a little surprising. The SMM blogs tend to get ranked higher in search because they tend to get more engagement from their users which results in more of their content being shared and more backlinks to their websites.