A new policy is going to be implemented for the apps in Google Play Store. It is to warn users about adverts in Play Store Apps. Starting in Jan 2016, all apps in the Google Play Store that contain adverts will be labeled as such, and that developers need to notify Google if this is the case for their apps. So from next year when you start downloading any app from Google Play Store, you will be warned if the app contains adverts.
By Jan 11, 2016, Google Play Store developers are asked to sign in to the Play Developer Console and declare whether your apps contain ads (such as ads delivered through third party ad networks, display ads, native ads, and/or banner ads). Post this date, whenever you try to make an update to your Google Play Store App, this ads declaration will be required.