“Annabelle” and its low-budget ilk offer big potential profits, but making a hit can be a scary proposition. (Gregory Smith/AP)

Hollywood’s new “it” girl is a creepy vintage doll named Annabelle whose eyes drip with the blood of her victims — and she’s bringing hope for the revival of horror films.

Annabelle ” blew up box-office expectations with $37 million in its debut last weekend, rivaling the opening of “Gone Girl” starring Ben Affleck. It’s one of the biggest openings of a horror film ever and the first of that category to draw such a crowd in years.

But what gets Hollywood most excited about its early success is the money that can be made off “Annabelle” and its copycats, which are cheap to produce and have huge profit margins compared with more costly action, comedy or drama hits.

“Annabelle” cost less than $7 million to make, compared with the $60 million spent on “Gone Girl.” That means the opening three days of “Annabelle” generated a hefty profit margin, while “Gone Girl” was still in the red. The most profitable film in history is the 2009 horror movie “Paranormal Activity,” which was made on a budget of $15,000 and reaped $193 million in global ticket sales.

The past few years have been tough for the horror genre, as studios have struggled to find another breakout hit that can generate lucrative sequels (“Paranormal” had four). No horror film out this year made more than $20 million in its opening weekend. Lionsgate bet big on the $65 million “I, Frankenstein,” for example, but total U.S. ticket sales were $20 million.

Annabelle Wallis, left as Mia, with the Annabelle doll in New Line Cinema's supernatural thriller, "Annabelle." (Courtesy Of Warner Bros. Picture/AP)

But like any good zombie, horror keeps coming back.

“As a genre, it’s never completely dead, because people always want to be scared,” said Phil Contrino, an movie analyst at research firm Boxoffice.com. “But it takes one movie that hits the right way, and where grosses are high, to get everyone in the movie business feeling good about the genre again.”

“Annabelle,” a New Line Cinema prequel to the 2013 movie “The Conjuring,” may have hit that chord with its return to traditional spookiness and gore. It received lackluster reviews from critics, doesn’t boast A-list stars and will probably be overlooked by awards panels.

But Warner Bros. is already planning a sequel to “Annabelle,” along with a sequel to “The Conjuring.”

“It’s not a franchise yet; we’ve only made one ‘Annabelle,’ but based on its response we are looking toward making another,” Dan Fellman, Warner Bros. president of theatrical distribution, said in an interview.

He said the movie did particularly well with Hispanics, whom the studio targeted heavily with radio promotions and bottles of “Annabelle”-branded holy water. The demographic tends to respond to horror’s religious references, including exorcisms, Fellman said. In the opening weekend, he said, U.S. border town theaters showed the biggest ticket sales.

Big potential revenue

Cheap but lucrative offerings such as “Annabelle” can help the studios fund more expensive, award-winning productions. That’s important in an increasingly risk-averse industry that likes to bet on such huge franchises as Disney’s “Frozen” and 20th Century Fox’s “X-Men” series. To ensure that a movie will do well in global ticket sales, produce sequels and sell T-shirts and theme park rides, studios are focused on what they call “tent poles” that can support a whole mini-

“All ego goes out the door when you greenlight a movie like ‘Annabelle,’ ” said Jeff Bock, a senior box office analyst at research firm Exhibitor Relations. “Even if it failed at the box office, it would probably still make a little money. Sure, it’s not a film from director Steven Spielberg, but that would cost at least $60 million to make. So that’s the balance that every studio has to watch.”

To understand the huge margins, look no further than the work of film producer Jason Blum, whose films include “Paranormal Activity,” “The Purge,” “Insidious” and “Sinister.” In total, his films cost $40 million to make and have reaped $1.2 billion in ticket sales.

“Annabelle” is a low-budget throwback in more ways than one, relying on decidedly old-school techniques to frighten moviegoers into buying tickets.

Produced by the prolific horror director James Wan and directed by John R. Leonetti, the prequel is set in the late 1960s and tells the story of the doll Annabelle that is referred to in “The Conjuring.” Both movies are based on the story of real-life paranormal investigators Ed and Lorraine Warren.

“Annabelle” begins with John Form giving his wife, Mia, a rare vintage doll. The wholesome, blonde Mia is charmed by the doll’s pigtails and satin white dress and puts it in the couple’s nursery. Annabelle, of course, unleashes unexplained terror and murder, tormenting the couple and everyone around them.

Familiar themes, tricks

The movie relies on traditional devices to spook audiences — the creaking door, suspenseful music, demonic possession. And maybe none of it is more time-tested than the murderous doll itself, which was milked extensively by the knife-wielding Chucky in the 1990s “Child’s Play” movies.

In that sense, “Annabelle” is similar to other releases coming this Halloween that revive old story lines and familiar monsters. Universal’s “Dracula Untold” will be released this weekend. “Ouija,” based on the spiritualist board game, is scheduled for Oct. 24 along with Lionsgate’s “Exists,” a horror film based on the legend of Bigfoot.

Such movies are a break from recent trends. Extreme gore dominated in the mid-to-late 2000s with hits such as the “Saw” series. More recently, hits such as “Paranormal Activity” revived the shaky “found footage” style pioneered by “The Blair Witch Project” in 1999.

“People are getting back to more traditional horror — with the creepy house with creaking floorboards,” Contrino said. “And people more moving away from the modern take on horror where people are working with cameras and phones as the focus.”

And they are bringing in important audiences — particularly women, Hispanics and millennials — who have otherwise turned more to online entertainment. Horror also does well overseas, where studios make the majority of their revenue. Bloody slashings and haunted houses spook a moviegoer in Buenos Aires as much as in Beijing.

New Line Cinema’s success with “Annabelle” comes to the rescue as parent firm Warner Bros. has struggled, ranking third in box-office revenue so far this year even though it put out more films than its top two competitors, 20th Century Fox and Disney.

Warner Bros.’ “Transcendence” cost $100 million to make, for instance, but since its March release has grossed only $103 million in worldwide ticket sales. “Blended,” starring Adam Sandler and Drew Barrymore, cost Warner Bros. $40 million and barely broke even in U.S. ticket sales.

“Annabelle” was made cheaply because it doesn’t rely on expensive computerized special effects or highly paid actors, and the studio isn’t pouring money into marketing the film the way it does blockbusters such as “The Lego Movie.”

Still, it’s hard to predict what horror audiences want. They quickly grow tired of certain styles just as Hollywood begins a cycle of copycatting.

Sony bet $30 million on the production of the crime thriller “Deliver Us from Evil” — which was heavily marketed by the entertainment giant — and made only $9 million in the movie’s opening weekend one year ago and $30 million in U.S. ticket sales.

Follow The Post’s tech blog, The Switch, where technology and policy connect.