Google had been hinting for months that app-install interstitials would become a negative ranking signal in search results, and about two months ago, they made it official.

Google announced that it was updating the Mobile-Friendly algorithm and test, advising sites against showing app install interstitials “that hide a significant amount of content on the transition from the search result page”.

As you probably know, Google introduced the mobile-friendly ranking signal earlier this year. It provided sites with a helpful mobile-friendly test tool so that they can make sure their pages were up to snuff. If a page passed the test, it would be good as far as that particular signal is concerned. The interstitials element adds a new factor to mobile-friendliness that will cause some that previously passed the test to now fail.

Google announced this week that the new addition is now officially live in the algorithm.

Google’s latest announcement was made at 2:24 (Eastern) on Monday. Have you seen any changes yet? Let us know in the comments.

In a post on Google+, the company says:

Starting today, pages with an app install interstitial that hide a significant amount of content on the transition from the search result page won’t be considered mobile-friendly.

Instead of full page interstitials, we recommend that webmasters use more user-friendly formats such as app install banners. We hope that this change will make it easier for searchers to see the content of the pages they are looking for.

For a little more background, Google had this to say about it in September:

After November 1, mobile web pages that show an app install interstitial that hides a significant amount of content on the transition from the search result page will no longer be considered mobile-friendly. This does not affect other types of interstitials. As an alternative to app install interstitials, browsers provide ways to promote an app that are more user-friendly.>

App install banners are supported by Safari (as Smart Banners) and Chrome (as Native App Install Banners). Banners provide a consistent user interface for promoting an app and provide the user with the ability to control their browsing experience. Webmasters can also use their own implementations of app install banners as long as they don’t block searchers from viewing the page’s content.

Ahead of the announcement, Google shared results of some internal testing it did with its Google+ app showing that an app install interstitial negatively impacted the user experience. Yelp CEO Jeremy Stoppelman was very vocal about his opposition to Google’s position on the matter.

After Google shared its study results, Stoppelman said on Twitter, “Google says stop pushing App downloads yet its own team push apps using same ‘bad’ designs. Is this about protecting consumers or protecting their search monopoly?”

He later wrote a guest post for Search Engine Land asking the same question. In that, he said, “While many users find apps by browsing inside an app store, another critical way they discover new apps is through mobile search engines, like Google. In this way, mobile search indeed serves a critical function to users: offering a bridge from the less desirable world of mobile Web browsing to a new world inside apps.”

He went on to discuss how apps threaten Google’s search business. After that, LinkedIn publicly questioned Google’s findings as well. They started off by saying that nobody wants Google+ for one thing.

“Naturally, an interstitial that interrupts the user experience to promote something that most people don’t want is bound to backfire,” wrote Omar Restom, mobile product manager at LinkedIn. “Google shouldn’t extrapolate based on this one case. ”

“Google admits that it was showing their interstitial even to users who already have the app – that’s bad mojo and fundamentally bad audience targeting,” he added. “Again, Google should only have shown this promo to people who actually want and need the app. The Google+ Team also violated Google’s own SEO policy by showing this interstitial on SEO Pages.”

He went on to make the case that LinkedIn’s interstitials work better because of better targeting and better creatives. Restom also backed up his argument with some numbers, comparing clickthrough rate, bounce rate and incremental app downloads driven between Google+ and LinkedIn.

Do you agree with Yelp and LinkedIn about Google’s findings? Do you think Google is doing the right thing with this ranking signal? Share your thoughts in the comments.

Images via Google