Just a quarter of search results on the first page of Bing and Google are the same according to a comprehensive analysis of US search results in 2013
New York, New York, October 10, 2013: On Bing, as on Google, pages from top brand web sites seem to have an automatic advantage which means they rank in the top search results positions. And content quality, social media signals and backlinks are all associated with pages that rank higher in searches. While only about a quarter (24.7%) of web pages (URLs) that appear on the first page of Bing’s search engine results are also included on the first page of Google.
The findings come from the SEO Ranking Factors – Rank Correlation 2013 for Bing USA study by digital marketing software and services company, Searchmetrics, which aims to identify the key factors that help web pages rank well in searches on Bing US and compares them with results from a similar earlier Searchmetrics study of Google US results. The new study is based on an analysis of search results from Bing.com for 10,000 popular keywords and 300,000 websites appearing in the top 30 search results and picks out the issues that correlate¹ with a high ranking on Bing (see accompanying Spearman Correlation chart).
Overall, a comparison of the results that appear on the first page of Bing and Google, revealed that 24.7% of the URLs listed were the same (but not necessarily in exactly the same position on the page), indicating the difference in the results presented by the two search engines.
Five other key findings from the study are:
1. Top brands rank higher on Bing as well as Google
Brands seem to automatically rank higher in Bing searches in the same way as they were found to do on Google in Searchmetrics’ previous study. However Google’s algorithm seems to be a little more effective at identifying brands and separating them from non-brands.
“Brands rank in the top positions even if they don’t meet certain criteria that non-brand sites have to – or don’t meet them to a sufficient extent,” said Marcus Tober, CTO and Founder of Searchmetrics. “For example, brand websites rank in the top positions on Bing and Google despite using keywords in the title or description much less frequently, offering less content on average and having a lower number of internal links. These are things that non-brand sites seemingly have to do more if they want their pages to rank well.
“And both Bing and Google consider it natural for brands to have comparatively more backlinks with the name of the company in the link text alone – what we refer to as ’brand links‘ – and still not be rated negatively as would happen for non-brand sites.“
Based on these findings, it seems Bing and Google give brands special treatment, helping them rank higher in search engine ranking pages (SERPs) according to Tober.
But Searchmetrics’ analysis indicates that the influence of brands does not seem as clearly defined on Bing as it does on Google.
“The brand factor seems mainly to affect the very first position in Google’s results, whereas for Bing, the first four to six positions show some kind of influence that seems to be caused by the brand factor. It seems like Bing is less sure about which sites belong to top brands and so deserve special treatment,” added Tober.
2) Backlink numbers are closely linked to higher rankings on Bing
In Bing search results (as with Google) the number of backlinks (links to a web page from other sites) remains very closely connected to how the page ranks. In fact, for Bing the number of backlinks has a high correlation of 0.29.
And while both Bing and Google try to reward pages that have a profile of backlinks that looks natural (not as though it was artificially created by linkbuilding experts), Bing seems less rigorous about this than Google.
“A natural link profile means a site should not simply have a large number of perfectly optimized links that include keywords it wants to rank for in the anchor text. It should have a proportion of ‘no follow’ links which do not convey ranking benefits on search engines and links that contain neutral ‘stopwords’ such as ‘in’, ‘and’, ‘to’ in the anchor text – as well as links that are us generic words like ‘there’, ‘here’ and ‘page’” explained Tober.
But the link profiles of high ranking pages on Bing are still significantly dominated by pages with both a higher proportion of links featuring keywords and smaller proportions of no-follow links, as well as fewer links with stop words said Tober.
For example Searchmetrics’ study found that on average, 52-53 per cent of the backlinks of websites ranked among the top 30 results on Bing contain keywords in the anchor text (which is about 10% more than Google). And 2% of backlinks of pages ranked in the top 30 on Bing contain a stop word (while on Google it is10%).
“The number of backlinks seems to be the most relevant metric for Bing, whereas the majority of the other backlink features – such as no-follow links or the presence of stopwords in the anchor text – seem not yet to be as relevant for rankings as they do for Google,” said Tober.
3) Social signals closely linked to higher rankings
Websites that rank in the top positions on Bing usually have a large number of social signals according to the study. In other words, well-ranked URLs have many shares, likes, comments, plus ones and tweets. And similarly the number of social signals seems to drop in line with the ranking of websites in search engine results pages (SERPs) – the worse the ranking, the lower the number of social signals. Google+ plus ones (0.34) have the highest correlation, followed by Facebook Comments (0.32). Tweets have a correlation of 0.30.
But Tober stresses that correlation is not the same as causation and the study cannot say conclusively that social signals can help pages rank higher on Bing – only that there seems to be a close association.
“There’s a lot of debate in the search industry about whether social signals directly influence rankings or are just closely correlated with rankings – because highly ranked pages will get more traffic and so attract more shares, likes, plus ones etc. On the one hand the data cannot help us say definitively which is true – but on the other hand, social signals are an important user quality signal which you would very likely expect to be taken into account by search engines,” added Tober.
4) Quality content is important for search rankings
Search experts believe the quality of content on web pages is an important ranking factor because search engines are keen to raise the rankings of pages with good, useful information and Searchmetrics’ analysis of Bing search results ‒ and the previous study of Google ‒ seems to support this to some extent.
As with Google, in Bing searches pages with more text are positively correlated with rankings (correlation 0.09) indicating that higher ranking pages have more text. But on average, pages ranking in the top 30 Bing results feature about 100 more words than URLs ranking in the corresponding positions on Google.
“If we assume that the existence of more text is an indicator of quality, then quality content is linked to higher rankings on Bing as well as Google, according to our study,” said Tober. “On Bing weactually found that this relationship exists up to a limit of around 700 words on average – after thisthe correlation tended to decrease. So you can’t just go on adding text in the hope it will continue to drive a more positive rankings boost.”
Bing seems to differ from Google with respect to how it values images –thought to be another indicator of quality content. In Google searches the higher the number of images on a website, the better the ranking, in general (correlation 0.08). For Bing, in contrast, the correlation of the number of images is much lower (0.03).
The study also highlights two other content factors that have a high correlation with ranking on Bing and Google; the number ‘proof keywords’ and ‘relevant keywords’ on a URL that are related to the topic a searcher is querying. This backs up the idea that the search engine algorithms take account of keyword semantics and clusters of keywords related to a topic when presenting search results.
5) On page technical factors are a must have
The analysis revealed that certain on-page factors² tend to have a low correlation because they are present on nearly every page that appears in the top 30 search results on Bing and Google (resulting in a low Spearman correlation coefficient).
“These factors tended to be the very basic on-page factors such as the existence of H1 headings, a keyword in the meta description and site speed. They are almost ever-present and should not be disregarded by SEO teams,” said Tober.
The low correlation for these factors does not mean they are not important according to Tober:
“Fulfilling certain on-page criteria is now not about achieving a favorable ranking; rather, it is the opposite: it is simply negative for the rankings when web pages do not meet these criteria. On-page factors are therefore considered more of a prerequisite for ranking higher in search results pages. “
Tober concluded by stressing that while the study highlighted those factors that correlate closely with a high Bing ranking (and compares these factor with Google), it is not possible to say that these factors definitively cause or influence the rankings:
“We can say that, on average, more well-positioned pages exhibited these features and more poorly placed pages did not. But only Bing and Google know what influences rankings on their search engines for sure – after all, they alone control how their respective algorithms behave.”
The detailed report which outlines the results from Searchmetrics SEO Ranking Factors – Rank Correlation 2013 for Bing USA study can be downloaded here.
¹ Correlations were calculated using Spearman’s rank correlation coefficient. A coefficient score of +1 implies a perfect positive correlation and a score of -1 implies a perfect negative correlation. In Searchmetrics’ analysis a high positive correlation coefficient occurs for a factor if higher ranking pages have that feature / or more of that feature, while lower ranking pages do not / or have less of that feature.
² On-page factors are those factors that the webmaster, publisher or their SEO team/agency can control directly, such as the text length, page titles, URL features and headings on web pages.
About the Searchmetrics SEO Ranking Factors – Rank Correlation 2013 for Bing USA study
The study analysed Bing US (Bing.com) search results for 10,000 keywords and 300,000 web sites, featuring in the top 30 positions, as well as billions of backlinks, Tweets, Google plus ones, Tweets, Pins and Facebook likes, shares and comments. The data was collected in July 2013. The results of the Bing study are compared to a similar previous study of Google US (Google.com) results collected in March and June 2013. The correlations between different factors and the search engine results on Bing and Google were calculated using Spearman’s rank correlation coefficient.