Here's an idea your comment made me think of: I wonder when are we going to see DLCs for movies?
Imagine - you buy the base Force Awakens for $10, and then they offer you extra movie parts - $1 for one in which Chewbacca does something silly, $2 for one which features an additional 10-minutes-long scene of starships shooting at each other, etc.
They've been doing this for years with deluxe editions on DVD and Blu-ray, providing things like deleted scenes, extended versions, and commentary tracks. You can pay one fee (or get a rental) for a bare-bones experience or pay more for a better one.
I sincerely hope not. If you bought a book but were told you could get an extra chapter of storyline added in for extra money, you'd wonder "Does it contribute to the story in any way?"
Ultimately, no.
Or "will the story make sense if I do not buy this extra chapter?". Hopefully yes; hopefully the story makes sense without this extra chapter.
I wouldn't want to watch a film with extra fluff that added nothing to the story, just for a cash-grab by the maker of the film.
Extra add-on features are always pointless: look at the Dreamcast and the add-on packs you could put into the controller. As it was entirely optional, none of the games could depend on it being there so had to cater for controllers without it, so this little LCD on your controller just ended up showing Rayman walking or dancing, and contributed nothing to the game.
The same is happening with Macbooks and iPhones, where developers cannot rely on the user having a "force touch" touchpad or iPhone 6nnnn (whatever it is), so cannot rely on that hardware feature being available; because of this, they cannot say "feature X is done by using force touch" because if you have a Macbook without that hardware, you can't use that feature. So it must get ignored to cater to everyone.
In the case of stories and films, the story must still make sense without the extra scenes. This makes the extra scenes pointless.
I hope not either. But this is a popular model in videogames, and it somehow both pissess off players and earns the studios tons of money.
You obviously can't apply it to every movie, but you could appply it to quite a few. For instance, there's little point in extra content for Inception, because the movie world is defined by the start and the end of that very movie, and as you said, it has to make sense in its basic version. But consider things with already established franchises. I Disney would start publishing DLC sub-stories to the Force Awakens, I'm betting that every hardcore Star Wars fan would feel obliged to see them. The world portrayed in the movie is much bigger than the movie itself, and is has communities formed around it. To participate in the fandom, you need to be up to date with the canon. I'm pretty sure it could work with Marvel Cinematic Universe as well.
Then there are movies for which such a move would be a gamble. LotR and Hunger Games are franchises too, but I don't think they're strong enough to support DLC money-grab.
Anyway, enough suggesting ideas to them :). I absolutely hate DLCs. I just couldn't resist discussing the concept in the abstract.
The Animatrix seems like a real example of something along those lines. A DVD of 6 short episodes that expanded on the Matrix story universe. They were done by different directors/writers/makers, like authorised fanfic or something. In my opinion it was a great addition, better than the full-blown sequels, and certainly not a distasteful cash-grab.
I think this could totally work for something like Inception too. The film has a backstory suggests at a wider context beyond what's shown in the scenes. Most stories do. That's why fanfiction exists.
I could see it being more like the DVD/BluRay Extras model - $5 for a pack of commentary tracks, $2 for deleted scenes, another $2-4 for the behind-the-scenes featurette, etc. It would be similar to the more successful DLC implementations, where a handful of enthusiastic users would make up a significant amount of the revenue.
It would be interesting to see how this would/could be applied to both rentals and purchases - rent the bonus features for $0.50-2 each, purchase them for $2-5 each or something like that.
That's the model that I think would actually be acceptable to all parties in the short to medium turn. I'd be happy to fork over $5-$10 ppv for a cinema release over the $23 I'd pay at the cinema. I'd still go to the cinema for bigger movies that I wanted to watch for the experience/sound/screen.