Do you have popup ads or interstitials on your website and in particular, your mobile website? You have until January 9, 2017 to fix that. Google announced this week that “pages where content is not easily accessible to a user on the transition from the mobile search results may not rank as highly”, which is Google speak for STOP with all the popups and in particular on mobile sites.
There are ways of making whatever popups you want to use less intrusive and therefore acceptable to Google, but if you are covering the content of your site with a popup, you or your web designer better get moving and spend the next couple of months fixing the issue before it comes back to bite you.
Above are some examples of popups you don’t want use on the mobile version of your website courtesy of Google.