Google came out on September 1, saying that giant ads for apps may lead to ranking declines starting on November 1. The algorithm update, the “app install interstitial penalty,” went live, but a whole day late on November 2.
The announcement was made by Google on various social networks, including their own Google+, saying:
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.
The penalty is going to be build right into the overall Google mobile-friendly algorithm. So far, there has yet to be seen complaints made by webmaster about being hit by the penalty yesterday. But I have a feeling we probably will.
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.
Check out the original story from September 1 to learn about which mobile configurations are at risk.