This post will give you a complete outline on what you can and cant do when it comes to avoiding the Mobile interstitial Penalty. The quickest way to ensure you are compliant is to grab your mobile device right now and bring up your website. If you are seeing advertisements before any site content you may be at risk of free falling down the serps.
Are you ready for the mobile index? There is really no excuse for you to not be. This has been spoken about for months, which as a business owner should have given you time to change and update any websites ready to take advantage of this change.