An In-Depth Analysis of Google’s Mobile Update with Real World Data

Google’s 2015 mobile update rolled out in April, cementing mobile-friendliness as a ranking signal.

At the time, it was the biggest update to Google’s algorithm in many years. Bigger than Panda or Penguin, both of which had a significant impact on search engines and website owners around the world.

We have access to a wealth of data and expertise that gives us exceptional insight into the real world impact of each Google update. So we’re looking back on this crucial 2015 algorithm change to share some of these valuable insights with you.

For the purposes of this study, we took a selection of websites across a range of industries, each with different levels of mobile friendliness. The aim? To uncover the impact of the update across the search landscape.

How Was Mobile Traffic Affected By The Mobile Update?

The graph below shows the average mobile traffic share from organic traffic for 16 different sites from 1st January 2015 to 31st March 2015:

Mobile Graph

We selected sites with varying levels of existing mobile traffic. This gave us a good overview of the update’s impact.

The average mobile traffic share across all 16 sites prior to the mobile update was 39.8%. At the time of the update, studies showed that mobile traffic was starting to overtake desktop traffic. This influenced Google to push out the mobile algorithm update in early 2015.

Now, let’s investigate what things looked like after the update rolled out on April 21st 2015:

Mobile Graph

Looking at the sites selected, the impact in terms of mobile’s share of overall organic traffic was anything from non-existent to business changing. The average mobile traffic share in the week following the update was 52.2%, an increase of 12.9%.

One site that didn’t have a mobile friendly design, saw a 57% increase in organic traffic share. Why? We noticed that competitor pages had already been reviewed and also lacked mobile friendliness. This meant the site retained its mobile organic traffic in the short term. We could see that the April 2015 Google update used a slow roll out process.

Traffic share for other sites only swung by a few percent. Of the 16 sites in this study, six saw their organic mobile traffic share change by 5% or less.

How Did The Google Mobile Update Impact Organic Mobile Traffic Levels?

We looked at the direct impact as a percentage of how many organic mobile visitors each site had lost or gained in the week following the update:

Mobile Graph

Mobile Graph

Above, we can see the fairly substantial movements in levels of mobile traffic that the update caused. However, it wasn’t in the direction you might expect.

Just two of the sites with no mobile functionality actually lost traffic. Six of the sites that we didn’t consider mobile friendly increased traffic.

It’s clear that Google didn’t consider these sites mobile friendly either. At the time, the Mobile User Experience scores from PageSpeed Insights for these sites ranged from 62 – 67.

However, the mobile sites that we tested showed a much more significant trend. Six of the eight mobile sites increased mobile traffic after the update.

The increases ranged from 2% to 159%. Clearly, some sites benefited more than others. The slow roll out process meant individual URLs were impacted.

Two sites that had excellent mobile functionality lost traffic. One by 2%, the second site saw a significant 18% drop. This particular site was in an extremely competitive space and all of its major competitors had added effective mobile functionality to their sites.

The major weakness of this particular site was content. For all the importance of mobile functionality and good user experience, the April 2015 update made it abundantly clear, once again, that high quality content is crucial for online success.

How Were Mobile Rankings Affected By The Mobile Update?

For this part of the study, we took a group of four large sites that ranked for a range of terms to give us an overview of a number of keywords. The sites were in different industries and ranked for thousands of terms each, so we had a very large sample set.

Two of the sites had very good, responsive designs. The other two didn’t have any form of mobile-friendly design. This allowed us to examine the impact of the update at either end of the spectrum.

Penalties on Non-Mobile Site Rankings.

This data showed us how sites without mobile functionality had their rankings penalised:

Mobile Graph

There was an average drop of 4.68 positions for the 100 terms that we tracked across the two sites without mobile functionality.

Ranking Benefits for Sites with Mobile Functionality

We also wanted to investigate how positive the change was for sites that had good mobile functionality.

There was an average increase of 6.32 positions for the 100 terms we tracked across the two sites with effective responsive designs, showing a positive impact for sites with good mobile user experience. This was in line with Google’s aim to put mobile-friendly content in front of mobile users.

However, rankings aren’t everything!

Net Effect on Organic Mobile Search Impressions

We took things a step further and looked across all 16 of the sites above to see how Google Webmaster Tools impressions changed.

Below is a graph showing 14 of the 16 initial sites and how mobile impressions changed in the week following the update. Two of the sites were excluded from this part of the study due to lack of data. In order to create a benchmark, we’ve compared the mobile impressions from the week following the update to the average of the previous six weeks.

Mobile Graph

The graph above shows the significant impact that the update had on non-mobile sites.

Out of the seven non-mobile sites, only one saw a very slight increase in mobile impressions from organic search of 2%. All of the remaining sites saw a reduction of between 2% and 40% in mobile search impressions. The average reduction in mobile search impressions for the non-mobile sites was 20.2%.

However, the interesting figures are actually across the seven mobile sites, where only two sites saw increases in the number of mobile impressions they’d received.

The rest all saw drops in the number of mobile organic impressions, despite having extremely high user experience scores for mobile. The average drop in mobile impressions among the mobile sites was 11.6%.

How Did The Mobile Update Affect Traffic From Different Mobile Operating Systems?

We also investigated the traffic sites received from different mobile operating systems.

At this time, iOS and Android were the biggest names in the mobile search market, so we focused on these systems.

We were particularly interested to see if traffic from Android devices was impacted more due to the link between Android users and Google personalisation.

Mobile Graph

In almost every case, Android traffic fell less than iOS traffic. On average, sites that lost mobile traffic retained 8% more Android traffic than iOS traffic.

Google tailors search results based on the user’s history. Android users are nearly always logged in when performing Google searches, so they’re more likely to be shown personalised results.

We know that iOS users are less likely to be logged into their Google account when searching. As a result, searchers, especially those who have visited the site before, are more likely to find the site if they’re using Android than iOS.

Were the results as you expected? We stay on top of changes in the search landscape to future-proof client campaigns. If you’ve noticed a shift in your online performance and need help pinpointing the cause, get in touch to discuss how a complimentary SEO audit by AGY47 can help.

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