As you know, interstitials are a great way to monetize your app while still providing a great user experience, with natural "commercial breaks" in your user flow. However, interstitials can take a while to load, and we know that this can make it tricky to implement since you must explicitly call loadAd() before calling show().

A common mistake is to call interstitial.show() in the onAdLoaded() callback. This makes the show() call not dependent on the app state, but on the asynchronous loading. Since the developer doesn't control when the onAdLoaded() callback happens, this provides a terrible user experience; the ad will show as soon as it's finished loading, which could be in the middle of another user interaction. This can result in policy violations due to accidental clicks.

Instead, we recommend loading the ad earlier in the lifecycle of the application, then polling interstitial.isLoaded() to see if the ad is ready to be shown. If it isn't ready, we recommend moving to the next state in the application.

We provide an example of proper interstitial loading in our sample "Impossible" game. When the game begins, we call loadAd() on the interstitial. When the user loses and clicks the button to try the game again, we check to see if the ad is loaded with isLoaded(). If it is, then we show an ad before starting the new round. Otherwise, we show a toast message that the ad isn't loaded and begin a new round.

This example focuses on the Android experience, but the same ideas apply to iOS. We hope our new interstitial example can help you create the best user experience as you integrate the Mobile Ads SDK into your apps. Check out this video for more on interstitial best practices. And as you're adding interstitials to your app, hit us up with technical questions on our developer forum!

 - Amy Quispe, Mobile Ads Developer Relations