Use Case
A Listener is listening to a track with a duration of 1:05 minutes, The widget owner calls a JavaScript or PHP function at the 1:04 time mark that may update a database, show an ad, or redirect the user.
The trigger effect and timing should be defined by the widget owner.
Personal Feedback:
My website rewards its members for doing various activities by updating a database column by adding points. So I would reward the listener for listing to the entire track by adding points if they are a registered member.