The SEO Ranking Factors - Rank Correlation 2013 from Searchmetrics has been released, and social media now takes center stage in SEO ranking. Of the top 10 factors that are most important to search engine optimization (SEO) ranking, social media shows up seven times. On the other hand, keyword links and keyword domains are losing importance.Specifically, Searchmetrics used data to learn what web pages that are well-positioned by Google have in common and what makes them different from lower ranking pages.The top 10 SEO rank influencing factors are:

1. Google+
2. Facebook shares
3. Number of backlinks
4. Facebook total
5. Facebook comments
6. Facebook likes
7. Pinterest
8. Tweets
9. Percentage of backlinks that use the NoFollow HTML attribute (so Google doesn't include them in its search algorithm)
10. SEO visibility of backlinking URL

Clearly, social media and backlinks are leading the way in building SEO rankings for specific content and web pages. Are you prioritizing them in your content marketing plan?The next most important factor to increasing SEO rankings is backlinks, but not just any backlink will do. Backlinks from quality sites are becoming more important every day. Building backlinks should also be a priority for content publishers.The study also found that using keywords in link anchor text and in URLs is not as important as it used to be. In fact, excessive use of keyword links can have a negative effect on your search rankings. Instead, focus on building organic links with high quality content. According to the Searchmetrics report, URLs that rank well typically have more text, a good internal link structure, and numerous media integrations. This is easy for Authoritative Content publishers who focus on creating high quality content.On the other hand, on-page SEO factors have become pre-requisites to getting good SEO rankings. The five most important on-page factors include: URL length, the position of the keyword in the title, the URL is not a subdomain, a description is included, and H2 tags are used.Finally, Searchmetrics found that brands are ranked differently by Google than other websites and publishers. For example, Google doesn't penalize brands for having a huge number of backlinks with the brand name in the link text. This could be flagged as a spam tactic for other online publishers.Searchmetrics created an infographic based on its findings, which is shown below. Take a look and see what's influencing SEO rankings in 2013.

Images: Svilen Milev, Searchmetrics