Beginning November 1, any mobile webpage that shows an app install interstitial on the transition from Google search results pages will no longer be considered mobile friendly. This update will cause websites that utilize full-page app install ads to be penalized in Google search results pages. The update does not affect other types of interstitials, so if your site is promoting a sale or offer using interstitials you should not see a negative rank impact.
What does this impact?
An interstitial mobile webpage is a screen or an overlay layer of content displayed before an expected content page. The use of full-page interstitials to encourage site users to install a mobile app has been a common and successful tactic for some time. However, after analyzing user experience data Google determined that interstitials covering a large majority of the landing page contribute to poor user experience and prevent users from getting the relevant content they expect to find. Google recommends using app install banners instead of interstitials, as they’re less intrusive and will not lower site ranking.
Image 1: Example of poor user experience with full-page interstitial:
Image 2: Preferred user experience with app install banners:
On average, mobile traffic produces a 35% share of organic search traffic, with some industries seeing as high as 50% share. After Google launched the original mobile-friendly update in April 2015, BrightEdge, a leading content marketing platform, reported seeing a 21% decrease in URLs now considered to be mobile-unfriendly on the first 3 pages of search results. Mobile websites continuing to use large app install ads after the November 1 update will likely see their mobile-friendly score decrease and their natural search visibility on mobile devices drop.