The latest ranking factors report from SEMRush is based on a study of 600,000+ keywords in local databases. It provides a very useful insight into the 12 most prominent and controversial factors, chosen to shed light on what really impacts search results
The main goal of the study was to identify any consistent patterns in the ranking mechanism that might help SEO consultants and website owners improve their rankings on search engines.
They say right from the outset that the formula is never simply improve factor X and you will rank higher for Y, but it is another very useful addition to our total sum of knowledge about SEO (search engine optimisation).
The report is an excellent evidence based analysis into what may work and what doesn’t in SEO and can be downloaded in full here: https://www.semrush.com/ranking-factors/
While the report is aimed at SEO professionals and digital marketers, we have summarised the main findings as it is very useful information for all website and business owners.
Their approach to the ranking factors study
SEMRush picked a dataset of 600,000 keywords and analysed pages and their rankings in search results.
To eliminate any human bias they used a machine learning algorithm called Random Forest to analyse the data and look for patterns. As a result they discovered a list of 12 ranking factors that influence where a web page might appear in search results and put them in order of importance: from most influential to least.
They then limited the scope to the first 100 positions in search results (up to page 9 or 10) as not many users will scroll further.
For each page in these results they analysed the following:
- On-page factors
- Backlink profiles
- Traffic data
There are different classes of keyword, some with higher monthly search volumes than others and these were classified as follows:
- Low volume (1 -100)
- Mid volume (101 -1,000)
- High volume (1,001 -10,000)
- Very high volume (above 10,000)
They ignored keyword difficulty (an evaluation of the challenges of ranking for a particular keyword due to competition and other factors) as it proved no better at classifying the keywords and volume. They also segmented the results within each volume class by keyword length.
Key findings of the ranking factors study
There were some key findings:
Winner takes all with number of website visits – Out of 12 factors analyzed, the number of direct website visits seems to be the most important page-ranking factor. Websites with higher authority consequently gain more traffic, and as a result, have a better chance of getting into the top of the rankings.
Improve the user experience – User behaviour signals such as time on site, pages per session and bounce rate indicate the authority of a website and influence its rankings as well.
Referring domains – A website’s number of referring domains can also indicate its authority, which together with the previously mentioned factors influences a website’s rankings.
Website security – although Google are encouraging certain websites such as e-commerce and sites with logins to go secure (HTTPS), there is little evidence that this boosts rankings, although a higher percentage of sites in the top positions use HTTPS for all keyword volumes.
Longer content – longer content pages are featured more prominently in higher positions.
On-page factors – Optimising websites for keywords on the page and body appears to have no significant effect on rankings factors on their own, but they contribute to a positive user experience.
As we delved deeper into the study it came up with some contradictory findings, that may be explained by correlation not causation. However, overall it chimed with our experiences of SEO for Small to medium sized businesses.
Website security (HTTPS)
All e-commerce sites should be secure as information from customers is encrypted as it travels around the web.
Also the main browsers, Firefox and Google Chrome are now flagging websites as insecure where they ask the user to enter a login or credit card information, so some other types of website should consider switching.
By migrating to HTTPS, you are being proactive in protecting your users’ security, which strengthens the authority of your website. However, it can be a costly undertaking and should be planned for properly.
For all keyword volumes, a higher percentage of secure sites in the top positions use HTTPS.
We have to wary about whether or not it causes a higher rankings on its own. Other factors come into play.
For example, at the time of writing we are number 3 on Google for web design rugby. Above us are two sites that don’t currently use HTTPS.
Having HTTPS for certain websites where users enter logins or credit card details increases trust and makes it more likely that they will stay on the site and explore more pages.
If you have 20,000 backlinks from 500 domains, you have 500 referring domains. Links are always important and black hat SEO techniques used involve placing links on thousands of low quality link farms of websites.
Google is a lot smarter these days, so these black hat techniques will cut a website’s ranking and could lead to penalty from Google.
In the study, they looked at the correlation between a website’s number of referring domains and the page position in search results,
They analyzed 600,000 search queries and calculated how many domains (taking the median value of that number for each position) are referring to each top-100 page’s website in total.
The main conclusions are these:
- The pages that rank higher have more backlinks from unique domains.
- The websites that appear on SERPs for high-volume keywords have significantly more backlinks than ones that appear for low-volume keywords.
- The top position does not necessarily have more referring domains – probably more authoritative domains.
To rank in the top 20 for high volume keywords you need a median value of 10,000 referring domains, making it a hard and long job to build links.
However for lower volume more niche areas, a relatively low number of links could have a significant effect on rankings.
On average, pages that rank higher have longer content. So, content length is important for your page’s success as long as it is valuable, well-written, and optimized, especially if you target high volume keywords.
There is a difference between general and more niche content: long-tail search queries have more content on average than short-tail ones.
For example, an average top-100 article on ‘graphic design’ will be shorter than an average top-100 article on ‘graphic design trends in 2017.’ Therefore be more concise on more general content.
This is where you pay attention to your Headings, use of keywords in title tags, headings, meta descriptions and body text. Some consider embedded video to be useful too.
The study checked whether keywords were present in what are generally considered to be important parts of the web pages for SEO.
The results show only moderate correlation between high and low positions with flat or shallow lines for all on-page elements. Here is the graph for keywords in the title tag.
Over 75 percent of the top-20 pages have keywords in their body and over 60 percent have them in their title. It seems to be a common practice, and pages optimized for high-volume keywords tend to have the keyword in body.
In general you need to make sure your website contents are useful. Sometimes over-optimising a page may make it less easy to read or dilute the message.
Also video was found to have very little effect on rankings unless your users expect to see video because of the nature of your business.
There are a lot of ways for visitors to find your website: direct traffic, organic search, paid ads, social networks, referring domains, emails, etc.
The study makes a strong link between website traffic and organic search rankings. They analyzed 600,000 search queries and calculated three values for all top-100 position: the number of unique visits per month, the total number of visits per month and the total number of visits excluding organic search traffic.
To see if organic search visits distort the final results, as there are more visits to the domain in the high-volume keyword group, they compared the total number of non-unique visits and the total number of non-unique visits excluding the ones that came from organic search.For high volume keywords, the boost to traffic on search engine rankings is quite pronounced. For lower volumes, the effect is not nearly as strong.
This could indicate that Google prioritizes domains with more authority when ranking the high-volume keyword group. Organic search is not the only thing you should be concentrating on. Direct and social visits are fuelled by your brand awareness, so building a strong brand image should be an essential part of your promotion strategy.
User signals and on-page factors
In the study, they analyzed several user behaviour signals such as bounce rate, the time that the user spends on the website in general and how many pages per session the user opens. These signals help identify user behaviour patterns and provide information on whether content is engaging.
Main conclusions include the following:
- The higher a page’s position, the lower its bounce rate.
- Sites that are higher in the search engine results have users spending more time on site in general.
- A top ranked site has more pages visit.
This is only a summary. We strongly recommend that you download the full report at this link: https://www.semrush.com/ranking-factors/
There have been some earlier excellent pieces of work on ranking factors.