Moz.com conducts its study on Ranking Factors every two years. The study conducted in 2013 showed trends that could be compared with data collected in 2011. Here are some important results that show factors that will affect ranking in 2013.
The study included taking in views of 120 SEOs as well a correlation study. The study involved over 14,000 keywords from Google AdWords across various categories. The top 50 organic search results from US Google were collected and SERPs were taken after Google launched the Penguin 2.0 update.
The correlations study through Mozscape index show that Page Authority happens to be the biggest correlated factor as per the study along with IPs, domains, and C-Blocks. Sub-domains proved to be larger as compared to domain correlations on a domain/sub-domain stage. SEOs paid a lot of importance to links as per the survey section of the study.
Even though Google has come down hard on any anchor text that seemed to be aggressively optimized, the data set revealed anchor text correlations for partial as well as exact matches. SEOs surveyed felt that anchor text distribution of an organic nature that included branded and non-branded, held more prominence as compared to merely link numbers.
On the keywords side, the study revealed that there was high correlation in terms of the title tag, meta description, H1 tags, and the HTML body. Keywords in titles as well as on the page were also quite important according to SEOs. There was hardly any correlation between structured markup including schema.org and Google+ author or publisher, which may mean that these are not yet utilized as signals for ranking.
Even though the importance of exact (EMD) and partial match domains (PMD) has decreased over the years as ranking signals, they do still rank quite high in SERPs. Social signals have not-surprisingly become very high correlated factors with Google+ rising higher than Facebook and Twitter.
On the other hand, most SEOs did not agree that social signals played an important role in ranking. There may be other factors such as links that may explain such a high correlation since these pass link juice after being crawled and indexed by Google.
To summarize the study results, around 40 percent of those surveyed felt that links play a very important role in the search algorithm. This was followed by on-page keywords. Around 7 percent of SEOs thought that social signals were not very important for ranking, which was in disparity to the indicated high correlations. SEOs also felt that there would be a shift towards in-depth analysis of site perception as viewed by users, structured data, social signals, and authorship, which was away from the current focus on exact match domains, anchor text, and other factors.