What is the SISTRIX Visibility Index?

The SISTRIX Visibility Index is a reference number for a domain’s visibility in Google’s search result pages.

The Visibility index is therefore well suited to measure and rate the success of SEO-actions or to analyse the consequences of changes to the Google algorithm.

Visibility index history for the domain zalando.de

You are also able to perform meaningful competition analyses with its aid. Due to this, you can, for example, identify the most successful websites in one segment, which are then consulted as Best-Practice examples (orientation towards the best) to increase one’s own success. This way, proven, optimal, or exemplary SEO-methods can be recognised and adapted.

Comparison of different Visibility indices of health portals

Comparison of different Visibility indices of health portals

The SISTRIX Visibility index is being calculated for every domain that exhibits noteworthy rankings in the search results on google.de, on a weekly basis, since March 17th 2008. From 2010 to 2011, the Visibility index was introduced for another seven countries and in 2015 three additional countries were added. The beginning of 2016 saw the start for another country.

Table: Introduction of the SISTRIX Visibility Index by country
CountryEvaluate searchresults onVisibility Index monitored since
Great Britaingoogle.co.uk26.07.2010

The Visibility index does not depend on seasonal cycles or external effects. That way domains like summertires.co.uk and wintertires.co.uk could, in theory, have the same value throughout the entire year. The one domain will gain its visitors on google rather in spring/summer, the other rather in autumn/winter.

Hence increases in the Visibility index do not necessarily have to mirror influence in actual traffic. If the domain summertires.co.uk manages to double their value for the Visibility index during the winter (and then keep this value), the doubling of the google visitors might only be significantly measurable the following season. Similar temporal deviations between the Visibility index values and the actual traffic can come up due to events like weather, holidays, school vacation etc.

Aside from these temporal influences, a high correlation between the Visibility index and the actual amount of visitors from Google can be observed. We will assume an expected click rate for every ranking position. In some cases, where the expected click rate does not match the actual click rate, peaks in the Visibility index can differ from the real traffic you might see. Examples for this are rankings by third-party sites to brand-keywords, multiple rankings within the top 10 and losses of ranking with below-average click rates, like with the Panda-Update.

The three crucial advantages of the visibility index for your SEO-work, compared to Web-Analytic-Tools like Google Analytics or the Google-Search-Console are:

  1. The available data can not only be accessed for one’s own domain, but also for competitors.
  2. The data is free from seasonal dependencies or trends such as, for example, weather, holidays and school vacations. This way the effects caused by SEO-actions of the individual market participants can be reliably measured and rated.
  3. Historical data for all domains going back to the year we started to monitor the country can be accessed without having to manually add any data.

How is the Visibility index calculated?

For the calculation of the Visibility index for all countries except Germany, the top 100 positions for 1.000.000 keywords, or rather keyword combinations (search phrases), are recorded and evaluated every week. These one million keywords were selected, so that they make up a good average for the country-specific search behaviour. This way, 100 million datapoints (1.000.000 x 100) are measured once a week as a basis for the Visibility index. We will measure and evaluate another 100 million datapoints for the Smartphone Visibility Index for each country.

To get an idea of the size of this set of keywords, a comparison is advisable. The current seventh edition of the “Paperback Oxford Dictionary of English”, for example, contains about one hundred twenty thousand words, phrases and definitions. Which covers all the words you need for everyday use. Therefore, a very large measure of samples takes place, making reliable and significant analyses possible.

Once the Keywords are recorded, the results are weighted according to the position and search volume for the particular keyword, in a second step. This means that place 10 for a very traffic-strong keyword like “apple” corresponds to a higher value than 1st place for a more seldom searched for keyword like “Display problem Iphone 3gs”.

When we weigh the positions we will take the different click rates per rankingposition into consideration.

All in all, the Toolbox tries to represent the actual click behavior of the Google-user for weighing each of the rankingpositions, as best as possible.

In the last step the weighted values are added up for every domain and then produce the SISTRIX Visibility index.

What is a good value in the Visibility index?

Your value in the Visibility index is good, when it’s better than the values of most direct competitors. This, of course, does not mean that it cannot be further improved.

How many points a domain can reach in the Visibility index depends strongly on the widths, depths and popularity of its contents. It should be clear that the website of a big newspaper with its large variety of subjects can reach more keywords rankings, which are being searched for more often than an online-shop for socks.

How economically satisfying the amount of points reached in the Visibility index is for a domain also depends on the basic business model of the website. If one runs a website which sells container-ships, 100 visitors per month, of which one visitor buys a container-ship, can be very lucrative. But if the business plan is build on advertising revenue, it can be difficult to generate enough sales with 100 visitors to break even on the server costs for the domain.

In this respect the Visibility index should be evaluated in comparison to the domain’s direct competitors. For a national yellow pages website a value of 30 points in the Visibility index can be considered fairly bad, when compared to the successful competitors who can reach values of around 100 points.

On the other hand, a value of 3 points in the Visibility index for an index of ornamental-fish, a segment with a considerably lower search volume, should be seen as good in comparison to its competitors.

Using the function “Competitors” in the SEO-Module of the SISTRIX-Toolbox, the direct keyword-competitors of a domain can be displayed and the Visibility index values compared with one click. This way, best-practice-examples can be identified rapidly. The way the results are structured makes it possible to grade the amount of points of an examined domain in its competitive-environment and to identify the best-practice-examples, towards which one can orientate oneself for an increase in success.

In November 2012, 100 domains in Germany had a Visibility index of at least 62,40 points. Most domains have a Visibility index of less than one point. When a domain has a very low Visibility index value, 0.001 points for example, it is advisable to set up an individual keyword monitoring within the Optimizer, to gain more ranking information on the domain.

What the SISTRIX Visibility index is NOT

The SISTRIX Visibility index is oftentimes confused with a SEO-traffic index. The SISTRIX Visibility index is no SEO-traffic index and is not supposed to be one.

We created our Visibility index so that we could condense ranking changes for a domain within Google’s organic search results into one key performance indicator. The Visibility index is extremely well suited to get a quick and comprehensive overview for the sum of all ranking changes. When there is a large decrease or a change in the general trend of the index, you can quickly make out the date where you should start your detailed evaluation.

Please consider that most keywords will not generate the same amount of visitors for different months and even weeks or days of the year. This means that a domain’s ranking for “Christmas trees” can be rock solid on position 5 throughout the entire year, while the domain will likely get 90% of their visitors during the Christmas season.

A traffic index would use the search volume for the specific month (or week or day) and multiply this value with the assumed click through rate (CTR). This graph would show peaks in the month with high visitor numbers and a valley throughout the rest of the year, considering the position does not change.

The Visibility index on the other hand uses the average search volume for the entire previous year in its calculation. This means that position 5 in May for “Christmas trees” will have the same value as position 5 in December.

If the domain would manage to increase their ranking from 5 to 2 over the course of the summer, the two index values would behave quite differently:

  • the traffic index would not be able to show the change, as the search volume values for the summer would be so low that no peak would show up.
  • the Visibility index would show the increase from one position to the next as the assumed click through rate (CTR) would increase while the search volume stays the same.

In both cases Google decided that the domain deserved a better ranking, but only the Visibility index is able to show this increase in Google’s trust, thereby enabling you to evaluate possible changes quickly.

Conversely, if the rankings should decrease from 5 to 10, the traffic index would, once again, not have enough visitors throughout the summer to show a noticeable change, which could lead to a rude awakening come next Christmas season. The Visibility index would show this decrease and give the website operator some time to get back on track, before the visitor season starts.

The SEO-traffic is dependent on the rankings but also on other factors, like the seasons, vacations and the weather. The Visibility index is a performance indicator that was made for SEOs. A SEO can change the rankings but not the change of seasons, holidays or the weather.

We wanted to create a key performance indicator which measures only the things a SEO has any influence over.