The longer the studios draw the characters' narratives out, the harder it is to persuade an audience to plunk down for theater seats. The third or fourth iteration of a film might appeal to a die-hard group, but finding newcomers to the audience can be tricky.
"Spider-Man," which was part of the boom in superhero movies in 2002, made a whopping 306 percent ROI at the domestic box office. Subsequent Spider-Man movies paled in comparison, with 2007's "Spider-Man 3" at only 54 percent.
But even to get to sequel territory, a character has to have the appeal to pull in millions. "Jonah Hex," one of DC's attempts at a comic-movie crossover, made just $10.5 million at the domestic box office on a budget over $47 million. Warner is rebooting the DC universe on the big screen with a series of interconnected films over the coming years.
"Ant-Man" may be in the same territory as "Hex."
"What is the crossover audience?" Nash asked. "If you have a big fan base for a character like Spider-Man, being able to translate that into a movie is fairly natural."
But Disney chief Bob Iger insists that he's not worried about a little costumed competition. Disney acquired Marvel in 2009 for $4 billion and has dominated comic book movies ever since.
"We like the Marvel slate that we have coming up," Iger told reporters at the Allen & Co. media conference in July in Sun Valley, Idaho, according to Variety. "We think they're unique in many ways and have no concerns [about competition] whatsoever."
As journalist Mark Harris wrote in Grantland last year, thinking of comic book TV and movies, "A bubble reaches its maximum pre-pop circumference when the manufacturers of a product double down even as trouble spots begin to appear."
Instead of movies, studios and their corporations are focusing on driving production to TV and online media platforms. Production is cheaper and marketing can be tailored to a niche audience that's more likely to be receptive to the characters.
As CNBC's Jane Wells reported from Comic-Con last week, the annual festival of nerdiness was virtually movie-free this year. Presenters instead focused on television offerings and virtual reality rather than the silver screen.