Websites may want to think twice before disrupting their visitors’ mobile experience with pop-up or interstitial ads. Google is warning of a crackdown on “intrusive” advertising by applying organic ranking penalties to search results come January. Web pages showing pop-up ads, either immediately or while the user is scrolling the page, will notice lower rankings in search results next year.

Not all sites using interstitials will be met with stiff web page penalties, as Google has diagrammed “responsible” interstitials that use a reasonable amount of screen space and aren’t deemed as much of an annoyance as full-screen pop-up banners.

More information can be found here: http://searchengineland.com/interstitialgeddon-google-warns-will-crack-intrusive-interstitials-next-january-257252