The iniquity of the interstitial

Sep 4th, 2015

Updated 12/01/17

Google has officially begun rolling out the intrusive mobile interstitial penalty


Google’s own research back in 2015 into the user experience of promotional mobile interstitial ads found that 69% of visitors confronted with the ad promoting the native Google+ app abandoned the site altogether. So it came as little surprise – following the Mobilegeddon algorithm update – that Google would add this to their list of factors determining ranking for mobile sites.

In September 2015, the search engine giant announced plans to crack down on mobile interstitial ads, adding:


When it comes to search on mobile devices, users should get the most relevant answers, no matter if the answer lives in an app or a web page […] sometimes a user may tap on a search result on a mobile device and see an app install interstitial that hides a significant amount of content and prompts the user to install an app. Our analysis shows that it is not a good search experience and can be frustrating for users.

Daniel Bathgate, Google Search Engineer


What does this actually mean for websites?

It means that mobile sites whose interstitial advertisements are deemed to hide ‘a significant amount’ of page content on transition from the search result page will no longer be considered mobile-friendly. It doesn’t currently impact desktop or internal links on your site.

Google said this means “pages where content is not easily accessible to a user on the transition from the mobile search results may not rank as highly”.

According to Google’s webmaster blog, examples of techniques that make content less accessible to a user include:

  • Showing a popup that covers the main content, either immediately after the user navigates to a page from the search results, or while they are looking through the page.
  • Displaying a standalone interstitial that the user has to dismiss before accessing the main content.
  • Using a layout where the above-the-fold portion of the page appears similar to a standalone interstitial, but the original content has been inlined underneath the fold.

Examples of interstitials that make content less accessible

Examples of interstitials that make content less accessible

Source: Google Webmaster Central Blog

Branded ads vs user browsing experience

Google’s research always seemed destined to confirm what many marketers – regardless of personal feelings – thought of this style of ad, and indeed the CTR was found to be 9%. However, where Google’s study departed from the ‘necessary evil’ view was in their follow up banner ad campaign which found that one-day active users increased by 17% while iOS native app installs fell by only a (statistically insignificant) 2%. This appears to have convinced Google that a move to penalise the use of interstitials would cause no real harm to a brand’s ability to advertise while the benefits to a mobile user’s browsing experience would far outweigh any negative impact.

Interstitial Ad
It may work technically – but has it worked for your consumers?

With a number of brands failing to take note of the early warnings (from Google’s ‘Webmaster Central’ blog) of the Mobilegeddon update forced to rush out last-minute mobile-friendly websites, it remains to be seen what percentage of mobile searches will ultimately be affected.


Contact us today to discuss how we can help to future-proof your mobile site.


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