Google have of plenty of notice that yesterday, January 10th, the Google mobile intrusive interstitials penalty would launch on January 10, 2017.
Google's Gary Illyes and John Mueller both confirmed it is indeed starting to roll out.
This only impacts interstitials that are present when someone clicks from Google's mobile search to your web page. It doesn't currently impact desktop or does it impact what you do from within your site.
Here are examples of bad mobile interstitials:
- 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.
Did you notice any site getting hit by this?