Common event types for ads.
The user clicked the advert.
The user closed the ad and has returned back to your application.
The ad has thrown an error. See the error parameter the listener callback for more information.
The user has left your application (e.g. following the ad).
When an ad has loaded. At this point, the ad is ready to be shown to the user.
The ad opened and is currently visible to the user. This event is fired after the
method has been called.