Warner Bros.

It wasn't just viewers who were scared out of their wits by "The Conjuring" this weekend; it was the big studios as well (save perhaps Warner Bros., which released "The Conjuring"). After all, this summer has seen several supposedly surefire blockbusters -- movies with big stars, big action sequences, and big fan bases from previous installments -- do big belly flops at the multiplex. (That includes Warners' own "The Hangover Part III.") And then here comes a horror flick with a modest budget (just $20 million), a restrictive R rating, no big names, no familiar title from a pre-existing property, and it opens at No. 1 with an estimated $41.5 million, setting a record for an original R-rated horror movie. And this on a weekend with three other wide-release movies opening, all of them more heavily touted.

To be sure, most pundits felt those films would be weak performers, but no one guessed that "Conjuring" would do as well as it did; predictions were generally in the $26 million to $32 million range. So how did "Conjuring" manage to outperform expectations so extravagantly? How did it manage to stand out during one of the busiest weekends of the summer? Here are some possible reasons behind the horror hit's taking possession of the multiplex.

It does have a star, sort of. That would be director James Wan, the auteur behind the "Saw" series and such recent horror hits as "Insidious." The Australian director may not be as well-known as Spielberg or Cameron, but among horror fans, he's a brand name.

It has a strong cast. Patrick Wilson, Vera Farmiga, and Lili Taylor may not be big box-office draws, but they're all fine actors who have done their share of horror films. Wilson was just in Wan's "Insidious." Farmiga has been in such horror hits as "Orphan" and "Joshua," not to mention the current TV series "Bates Motel." And Taylor has been in horror hits for well over a decade, going back at least to 1999's "The Haunting." So, between the director and the cast, there's a group of filmmakers who knew what they were doing.

There was a dearth of horror at the multiplex. Not since "The Purge" a month ago has there been a horror hit. At a time when everything is giant action spectacle, raunchy comedy, or family cartoon, that leaves a big opening for a film like "The Conjuring" to take advantage of.

"Based-in-fact" horror is a successful subgenre. Horror movies supposedly based on real-life events tend to do well, from "The Amityville Horror" to "A Haunting in Connecticut" and many other recent exorcism-oriented movies. This one was supposedly based on the real experiences of the paranormal phenomena investigators played by Wilson and Farmiga, an element Warners played up in its marketing.

The movie had a novel marketing campaign. Instead of a conventional trailer, Warners released an extended clip from the film, a creepy sequence of Taylor and her kids playing hide-and-seek in their haunted house. That turned out to be a surprisingly viral and effective way to distinguish the film from, oh, every other haunted house movie you've ever seen.

The competition was weak. Sure, there were three other movies opening in wide release this weekend, but at least two of them were duds. Sorry, Ryan Reynolds, but you're not a box-office draw. That was apparent from the third-place debut of "Turbo," the cartoon in which Reynolds voiced the lead role, and in the even more dismal seventh-place debut of his action comedy "R.I.P.D." (Also, sadly, Jeff Bridges is not a big box-office draw, even when he's channeling his own performance as Rooster Cogburn from the 2010 smash "True Grit," as he seemed to be doing in "R.I.P.D.") The third new movie, "RED 2," opened in fifth place and did about as well as it was expected to do, but it was arguably playing to a different audience, mostly older and male. Which brings us to...

Women are underserved in the marketplace. Horror films do especially well with women, and that includes "The Conjuring," whose audience was estimated by studio polling to be 53 percent female. With "RED 2" and "R.I.P.D." aiming at men and "Turbo" aiming at kids, that again left a space wide open for "The Conjuring." Really, it's a wonder that Hollywood decision-makers keep treating hits like this one or the recent "The Heat" as flukes when they're simply satisfying a niche -- if you can describe half the population as "a niche" -- that Hollywood often ignores.

The movie delivered on the hype. Reviews were strong, and so was word-of-mouth, as measured by its A- grade at CinemaScore. People were recommending the movie because they found it genuinely frightening. In a season of dull action movies and chuckle-free comedies, a movie that does what it sets out to do and doesn't disappoint is no small accomplishment.

Moviefone Live!: 'The Conjuring'
The Conjuring Movie Poster
The Conjuring
Based on 35 critics

In 1970, paranormal investigators and demonologists Lorraine (Vera Farmiga) and Ed (Patrick Wilson) Warren... Read More