There was once a time when the credits of a movie meant the end of the show. The audience would actually get up and leave the cinema. That is no longer the case, with films now employing the post-credit scene to either further a shared universe or just pay a bit of fan service.
Marvel, the Kings of the post-credit scene, have been known to use both of these methods and have almost trained their fans to stay in their seats right up until the lights come on and they are asked to leave. The reason these scenes are so effective is because it allows Marvel to give viewers a glimpse of what they can expect for upcoming movies, or put one last smile on their faces.
Thor: Ragnarok will be no different to any other Marvel movie in this regard, and director Taika Waititi is no stranger to the post-credit scene. Though Scott Derrickson directed Doctor Strange, it was the Ragnarok director that actually shot the film's mid credit sting.
He will get the opportunity to do so again for the upcoming Ragnarok, and there are a number of different directions he and Marvel could take...