With regular algorithm updates, search engine optimization is a game with ever changing rules. What helped websites achieve top position in search rankings last year (sometimes even last quarter) is frequently no longer a high priority or even relevant to current SEO strategies. To help digital marketers better understand the factors that determine which websites rank higher in search results than others Searchmetrics, a leading search analytics technology company, recently published their Ranking Factor - Rank Correlation study. The study evaluated factors that differentiate better-positioned websites from pages placed further back in the Google.com organic search results, and compared those factors to rankings in 2012 to current rankings in 2013 to determine changes and trends.
The study by Searchmetrics analyzed 10,000 keywords that led them to:
- 30,000 SERPs (search engine result pages)
- 300,000 titles, descriptions, URLs, etc.
- Approx. 150 GB of data
- Approx. 600,000 AdSense blocks
- Approx. 5,300,000,000 backlinks
- Approx. 4,150,000,000 Facebook shares
- Approx. 12,950,000,000 Facebook likes
- Approx. 600,000,000 Facebook comments
- Approx. 1,000,000,000 tweets
- Approx. 330,000,000 Google plus ones
- Approx. 14,500,000 Pins
When analyzing this vast amount of data Searchmetrics focused on six categories of ranking factors to determine how top rankings are achieved:
- On-Page Coding
- On-Page Content
- Social Signals
- The Brand Factor
- The Special Role of Wikipedia
The following are some of the takeaways from the study that I found most interesting from the first four categories analyzed.
Changes in On-Page Coding Factors
The study found that while meeting specific on-page criteria does not have a direct positive impact on rankings, not meeting them does have a significant negative impact. In addition, Google now discounts the "keyword in the domain" factor, and instead puts more weight on having keywords in the page title and description, and the mere presence of a description, H1 and H2 on each page. Other factors that have increased in importance are the speed at which pages load and the relevance of the page content to keyword searches.
Changes in On-Page Content Factors
A finding that was not surprising was that quality content continues to become a more prominent factor in rankings. The study found that the majority of high-ranking URLs have a large amount of text and multimedia content. In addition, having a good internal link structure is becoming a more important factor.
Changes to Backlink Factors
Quality backlinks continue to be one of the most important off-page ranking factors for SEO, and there is still are high correlation between the number of links back to a website and high rankings in search results. However, there are more factors that play a role in Google's analysis of backlinks, including:
- Natural backlinks
- Balanced mix of "nofollow" and "follow" links
- Multi-word anchor texts
- Quality of the link source
The Rise of Social Signals
Compared to 2012, social signals now play a more prominent role in ranking websites. The study by Searchmetrics showed a strong positive correlation between social signals and better rankings. Social signals have become a more important factor because they can lead to faster indexing of content in search engines. Overall, top ranking URLs had an abundance of likes, shares, tweets, and plus ones. In particular, it is clear that the more plus ones that a URL receives the higher it is ranked in search results.
An item of note that I do want to mention is Searchmetrics' findings in regards to Brands:
Brands are the exception to the rule. The decoupling and separation of the "brand" factor from the "keyword" factor has been put into practice very well by Google. The majority of top positions in SERPs are occupied by brands and thus websites that mostly do not meet some of the basic principles (often on-page factors). via Searchmetrics
For an easy recap of the Searchmetrics Ranking Factors - Rank Correlation 2013 study check out the highlights in the infographic below or download the Searchmetrics Ranking Factors - Rank Correlation 2013 sutdy.