Dive Brief:

• Google has rolled out the expected intrusive mobile interstitial penalty, per Search Engine Land. The penalty, which intends to lower web rankings, was announced around six months ago but went into effect Jan. 10, Google confirmed. 
• Interstitials subject to penalty include popups that cover the main content immediately after navigating to the page or while visitors are looking at the page; standalone interstitials that users have to dismiss before accessing page content, and page layouts where above-the-fold content appears similar to a standalone interstitial with original content inlined underneath the fold, according to Google.
• Only mobile pages with intrusive interstitials directly tied to search results are hit with the penalty, meaning websites using the format deeper into their structure won’t be affected.

Dive Insight:

If they haven't already, marketers should take the time to scrutinize their mobile sites and ensure they are in compliance with Google's policies to support mobile search optimization. On the user end, consumers should welcome the move by Google to help clean up mobile web navigation and overall experience.

Interstitials are viewed by many as one of the most intrusive and ineffective digital ad formats and are often cited in discussions around the rise of ad blocking technology. As the marketing world becomes truly mobile-first — and as mobile ad blocking increases along with desktop — brands need to focus on improving the quality of their advertising offerings to foster engagement, which is not likely to happen with a pop-up.  

However, some interstitials get a pass from Google if "used responsibly," per Search Engine Land. Interstitials in response to a legal obligation such as age verification, login dialogs for content not publicly indexable such as private content and banners that only use a reasonable amount of screen space and are easily dismissible might be acceptable.