Quality content and other on-page factors have become increasingly important for SEO in recent years thanks to Google’s various algorithm updates aimed at cracking down on spammers and sites that offer a poor user experience.

And a new report from Searchmetrics shows just how the influence of on-page SEO has changed in the past 12 months by examining the correlation of various factors with high Google rankings. 

Virtually all criteria – ranging from the image count to Adlinks – have apparently increased in importance, with a site’s word count showing the biggest difference compared to last year.

‘Title character length’ is one of only two factors showing a slightly negative correlation, however this can be interpreted positively: the shorter the page title of a document, the better the ranking.

Correlation changes since 2012

The report gives a full run through of the important factors, but here’s a look at a few of the ones that jumped out. The research is based on analysis of 10,000 search terms from Google UK, using the first three pages of results.

It’s important to point out that the findings are a correlation rather than causation, but it does seem to suggest that there’s some relationship between search rankings and the various different factors.

Word count

Looking more closely at word count as a factor, the report shows that pages that rank in top positions have a higher word count than websites positioned at the lower end of SERPs.

The one anomaly is the presence of brand sites, which occupy a hallowed place at the very top of Google search results.

Brand websites seem to have lower word counts on average than search results on the first SERP. Consequently pages ranked first have 407 words on average, which is 120 words less than pages ranked 2nd (529 words).

Internal links

The report shows that pages appearing at the top of search results tend to have a greater number of internal links than pages achieving lower rankings. The anomaly is again brand websites.

However it’s not just about the sheer number of links on each page – internally-linked keywords as a link text play a role in the optimal distribution of the ‘link juice’.

The current rule of thumb suggests using ‘hard’ links internally (i.e. with keywords) and ‘soft’ links externally (i.e. generic/stop words/more words in the anchor, brand links, etc.).

Advertising less negative than before

In last year’s report there was clearly a negative correlation with advertising integration and good search rankings – even for AdSense, Google’s own ad product.

In effect, this meant that well-ranked sites had fewer adverts than those that ranked lower. The situation has now changed somewhat so these correlations are close to neutral.