Interstitial Ad
Ad formatsA full-screen ad that covers the whole app or page at a natural break — between game levels, after an article, or on app launch. It commands attention and pays a high CPM, but bad timing wrecks the user experience and Google penalizes intrusive interstitials on mobile web. Standard sizes are full-screen portrait and landscape (e.g. 320x480, 480x320).
Example
A full-screen 320x480 ad shown between levels of a mobile game, with a close X in the corner.