It all comes down to numbers. Yet again.
Waterworld was a notoriously big-budget, low box-office sci-fi adventure, featuring Kevin Costner, Dennis Hopper and an awful lot of quasi-Mad Max-y floating sets.
I have to admit, there were bits that I really liked - the guy who lives in the fuel tanker, for example. There's a moment with him that seemed like something from a Jeunet movie.
The film pulled in under $90 million at the US box office, against a budget of $175 million or so, or perhaps as much as $235 million - depending on which bean counter you believe. This was in 1995, so what ever budget you do settle on, all of those numbers would have been much higher today.
But forget inflation and just look at the ratio between the outgoing and incoming. It's steep enough that there was never any chance of a sequel.
But that's not the end of the story. Or the counting.
The film has gone on to have a second life in home entertainment, and according to Forbes, it has proven to be quite a hit for the SyFy channel. 400,000 people watched it last time and that, by their measure, is a good result.
So Dave Howe, the network's president, is considering a spin-off TV series. It has apparently been "talked about endlessly" and remains a real possibility.
At the same time, SyFy are "actively developing scripts" for a move into feature films. There's no news on any of these in the Forbes piece, but the implication is, they're applying different criteria as to what would make good TV and what would pass on the silver screen.
Anybody who has ever seen Sharktopis will be grateful for that at least.