You should send the teaser_shown event when the user can see the teaser, e.g. the button via which he can access the adjoe SDK from the SDK App. Trigger this event when the teaser has been successfully rendered and would successfully redirect the user to the adjoe SDK. It should be triggered regardless of whether the user has actually clicked the teaser or not. This event is mostly appropriate for uses, in which the functionality of the SDK App and SDK are kept separate to a relevant degree.