Here's a report on the status of Spider-Man: Turn Off the Dark on Broadway. The article wonders just what it is that's driving audiences to see this show and make it a sell-out in its never-ending previews. I suspect for an awful lot of those folks, the motivating factor to buy tickets is to be able to say to their friends, "I saw Spider-Man."
The piece also notes skepticism that it can ever recoup its costs and show a profit. In addition to the extraordinary expense in mounting the show, there's the fact (unmentioned in this article) that many of the traditional ways a Broadway show can make money are not available to this one. First and foremost, its elaborate special effects make it impossible to mount a number of touring companies…perhaps not any. Spamalot, for example, is now touring America with at least one production that can go into a city, set up and do three or four nights before moving on. If you simplify this Spider-Man show down to make that possible, you remove most of what people might pay to see. In theory, you might be able to set up another production in another city that would stay put for a few years — Las Vegas is the most obvious choice — but it sure sounds like a risky and unlikely investment. Overseas, maybe.
A lot of Broadway shows go into profit because of a movie sale…but someone already owns the film rights to Spider-Man. It's doubtful there can be a movie and even if there ever is, the money for the rights would not all flow back to the producers of the musical. They'd probably see a small fraction of it. They also probably have to share the merchandising income from t-shirts and such to a degree that other shows do not. It's pretty much going to come down to selling tickets on Broadway and hawking the CD. Most shows don't go into the black on those alone. And of course, most shows don't cost what this one does just to run each week.