"Movies are so rarely great art that if we cannot appreciate great trash we have very little reason to be interested in them." - Pauline Kael

You've heard the buzz. You've followed the rumors. You may even have bought the hat or the t-shirt, or photoshopped your own CNN title crawl involving the words snakes, plane and a couple obscene gerunds. Now, after months of waiting, Snakes on a Plane -- possessed of the simplest, the-title-is-the-pitch plot in years -- has opened without screening for critics, which is why I found myself at a semi-full Midnight show along with a crowd who, in many cases, brought their own rubber or stuffed snakes. Between TV appearances, interviews, recording material for "custom-made" promotional phone messages and photos draped in legless reptiles, star Samuel L. Jackson's been working overtime to plug, push and pitch Snakes on a Plane -- and looks like he's having a great time.

Of course, if you're going to bet your career on a roll of the dice, you'd probably want to look enthused as you toss them down. Jackson may be a movie star -- he's internationally known and, with his rippling vocal cadences, loved and mocked by pop-culture fans worldwide -- but he's yet to top-line a movie that opens to more than $35 million dollars. (Much like Jeff Goldblum, the total box office of films Jackson's been in is formidable -- but those are films where he's most definitely not the main attraction.) So, why not make a crazy-ass bet on some snakes?

Jackson plays FBI agent Neville Flynn, who is escorting Sean Jones (Nathan Phillips), a witness to a brutal gangland slaying in Hawaii, to L.A. to testify. It would be a serious setback for gangster Eddie Kim (Byron Lawson) if Jones were to testify; Jones can't be allowed to make it to L.A. alive. And so, in one of the most ornate and inefficient assassination plots the silver screen has shown us since the heyday of Wile E. Coyote, Kim arranges for an assassin to load the plane with a time-release box of ... poisonous snakes. Kim snaps at an underling who questions the plan: "Don't you think I've exhausted every other option?" Well, let me think: Guns ... knives ... garrotes ... No, Eddie, I don't think you have. When Hank (Bobby Cannavale), Flynn's ex-partner on the ground in L.A., is told of the situation, he asks the question we all would: "What kind of insane plan is that?"

So we meet all the passengers, who apparently are flying Hawaii-to-L.A. as part of their connecting itinerary back to cliché-town: The stewardess on her last flight (Julianna Margulies), the hearty good-ol'-boy pilot (David Koechner), the rap superstar (Flex) and his bodyguards, the two kids flying alone. Director David R. Ellis tries to keep things moving -- with a plot this thin, if you don't skate over it fast, you'll fall right through it -- and the script (credited to John Heffernan and Sebastian Guiterrez) is as hole-ridden and threadbare as a well-loved sweater.

But we aren't here for Chekhov; we're on board for snakes. And once the snakes are unleashed, you get a sense of just how Snakes on a Plane is going to go wrong: These people don't even know how to craft the rhythms and pleasures of good trash. There's plenty of shock in Snakes on a Plane -- think of a body part, even those naughty bits in the swimsuit area, and rest assured that the film shows us someone getting fanged there -- but there's almost no suspense. Worse, after an initial snake-gasm of an attack -- all hissing and shrieking and dying, oh my -- the film slows down significantly, resulting in a third act that's more an exercise in tedium than it is in tension.

Jackson gets to play the cool action hero with a low boiling point yet again, speaking his dialogue in tones so polished you can hear the italics: "I've had it with these muthaf*cking snakes on this muthaf*cking plane!" That line -- and much of the film's ultra-violence -- were added to the movie as part of re-shoots, after the voice of the people seemed to suggest to New Line that if you're going to make a movie about snakes on a sealed vehicle, you might as well tighten up your undergarments and go for the R-rating.

But, even knowing as little as I do about dairy production, I do know you can't make cheese overnight. (Yogurt, sure; try it!) So-bad-they're-good movies are not born, they're made -- a slow process of time turning trash into treasure, thin trails of camp growing through the idiot mass of a bad movie like a blue-vein mold that adds flavor to a nice Stilton. Showgirls; Beyond the Valley of the Dolls; Plan 9 from Outer Space. None of these are good movies, but they've endured in part because the people making them thought they were making good movies, and that hint of high-minded delusion makes all the difference. The people behind Snakes on a Plane were trying to make a bad movie, and in that they've succeeded.

There are a half-dozen things that could have made Snakes on a Plane a better film: A tighter third act, casting an actor opposite Jackson to play the witness with even a hint of charisma, an ending that satisfies our dimwit thirst for movie justice, giving the designated sacrificial lamb characters even a line of dialogue before they get fanged to death. Yet it feels like after the pitch meeting casting Jackson and crafting the promo plan, everyone let out a big sigh of relief at how this baby was going to sell itself and quit working. Snakes on a Plane has an irresistible title and an impressive promotional campaign -- but pitches aren't plots, and marketing isn't moviemaking.