Can you imagine if a company only made one thing? What if that one thing was so relevant, they could successfully market and sell it to anybody? That'd be mighty convenient.
That's why Mattell invented He-Man for boys when they couldn't stomach only selling to girls.
But this is not the reality. Many things must be made and companies must instead market those things to specific people. We'll over-simplify this shared universe comparison for a moment and say Superman and Wonder Woman must both be made, if we want to make All The Money.
One more "but," and it is the killer whale of "but's": What if all those specific people were motivated to buy all those many things?
Why does it feel like all movies sequels?
A shared universe is such an appealing prospect for an industry as expensive as movie-making. It means everything is a sequel to everything else. It means everyone will be motivated to see whatever they produce.
While we live in a world where connectivity has made entertainment continuous, we've been conditioned to view time misaligned as time wasted. We want every Facebook post to include a follow-up debate. We want a never-ending SnapChat stream.
We want every movie to be a sequel to another movie. We want all the time spent in a universe to be cumulative.
But how do studios make money off connected movies?
Shared universe movies are pre-packaged homework exercises. Keeping everybody busy is linked to black numbers and green up-arrows on accounting sheets somewhere. Viewers can complete as much or as little of the extracurricular as they like—all the studios have to do is develop a curriculum to pack as much Wonder Woman backstory into the newsfeed as possible.
They want mindshare. They want you thinking about one movie, like Wonder Woman, and how it connects to Batman V Superman. This is so much more effective marketing than stacking billboards alongside highways and buying up TV adspace. This new era of marketing worms down into your brain. It's gonna be on the test when you go get drinks after the screening.
Read up on teaching-theory, and you'll discover how much more effective the activity of self-motivated thought-formation (homework) is than simply sitting in a lecture hall (that'd be the TV ads, in this case).
This helps the studios keep viewers engaged and make money off formerly-unrelated films. You all have already done the homework and been lectured on Superman, why not go see Aquaman?
(This is Aquaman. Aren't you curious? Not pictured: aquatics; men.)
What comes next?
These shared universe movies will be judged on their quality. They're clicking with the current audiences that grew up on cartoons, comic books, and pre-existing knowledge.
But that's going to run out very quickly when the children raised on the X-Men TV show are usurped by the younger generation bred on YouTube personalities.
The marketing prospect is attractive at the moment. Studios would be well-served to understand WHY this format is drawing in audiences, who they are, and what they're enjoying. They need to begin preparing for what comes next in 5-10 years, too.