Released just before the crowded Christmas movie season, Sony’s “Anyone But You” seemed destined to be anything but a box-office hit — especially after it tallied just $6 million in ticket sales during its opening weekend.

However, the film’s box-office success was as much of a slow burn as the romance between its main characters played by rising stars Glen Powell and Sydney Sweeney.

In the seven weeks since, the romantic comedy has tallied $170 million globally, including $80 million from domestic theaters, according to data from Comscore. The film had a reported budget of just $25 million.

A sleeper hit at the box office, the film is a “healthy sign” for the romantic comedy genre and other mid-budget Hollywood flicks, said Scott Meslow, author of “From Hollywood With Love: The Rise and Fall (and Rise Again) of the Romantic Comedy.” But it remains to be seen if other rom-coms can repeat its success.

As studios chased big-budget superhero flicks after the success of Marvel’s interconnected cinematic universe, Christopher Nolan’s Batman trilogy and DC Studios’ “Man of Steel,” the rom-com found itself on the cutting room floor — and then as padding for streaming services.

Between 2004 and 2010, Hollywood consistently released between 15 and 25 romantic comedy or romance films each year. But from 2011 through last year, there were less than 15 new rom-com or romance releases per year, with most years falling below 10.

Meslow said there was no rom-com “kill shot,” a film or series of films that sparked the decline in theatrical releases of the genre.

Instead, it came after media companies changed their priorities.

“Studios are, at the end of the day, businesses,” Will Gluck, the writer-director of “Anything But You” and the filmmaker behind “Easy A” and “Friends with Benefits,” told CNBC. “So, if they start to see a certain thing is successful, they’re going to try to replicate that success. So, I don’t think there’s an inherent bias against rom-coms and comedies.”

Studios saw action or superhero movies with $200 million budgets and billions in box-office returns as a priority over smaller-budget films, which may have been profitable, but less so in comparison. Now, as superheroes fall out of favor and Wall Street wants to see profitability from direct-to-consumer streaming platforms, the romantic comedy genre is poised for a comeback.

Gluck’s “Anyone But You” proves audiences will still turn up for romantic comedies in theaters.

The film’s performance builds on the success of two rom-coms from 2022. Paramount’s “The Lost City” generated nearly $200 million at the global box office on a budget of under $75 million. Universal’s “Ticket to Paradise” snared nearly $170 million globally on a budget of $60 million.

While “Anyone But You” had a slow start at the box office, ticket sales increased in both its second and third weekend in theaters. And when sales started to dip, they fell just 27% or less in each of the next five weeks. Typically, films will see sales drop around 50% to 70% in each week after their opening weekend.

Gluck attributes much of the film’s box-office popularity to word of mouth and the power of TikTok.

In the wake of its release, users on the social media platform began making short videos of themselves singing and dancing to Natasha Bedingfield’s 2004 single “Unwritten.” The song is featured in the film, and cast and crew are seen singing and dancing to it during the final credits.

“It would not surprise me at all if this became a textbook case of modern Hollywood marketing,” Meslow said. “It’s really harnessed TikTok and the stars’ presence on it better than probably any movie ever released.”

Hollywood will now find out if “Anyone But You” is a unicorn or a replicable theatrical strategy. The film benefited from several key factors, including a blockbuster-free January and limited direct competition.

But the industry is already leaning into a strategy that relies on potential sleeper hits like “Anyone But You.”

Major studios have pledged to bring more mid-budget films back to theaters. Those movies are able to fill the gaps between large tentpole features and provide consistent box-office dollars. More films also means more chances for studios to advertise future releases to the public.

While some films will still be released only on streaming platforms, Hollywood has rediscovered the importance of theatrical as part of overall downstream revenue. A film’s debut in theaters creates buzz and a sense of quality that follows it through on-demand sales and onto streaming platforms.

Notably, Sony’s “No Hard Feelings,” which tallied $83.8 million globally in 2023 on a budget of $45 million, became a top-streaming film on Netflix when it was released on the platform in October.

“Anyone But You” is destined for Netflix after it wraps up its theatrical run, as part of a streaming distribution deal with Sony signed in 2021.

Gluck, who enjoys taking on a wide variety of projects, expects he will continue to write and direct films like “Anyone But You” going forward.

“I think I’d rather take a gamble on a mid- to low-budget movie than a $200 million movie,” Gluck said. “Because my whole career has been mid-level budget movies. But to me, the fun part is always outperforming. It is always great when the expectations are low … it’s just it’s really fun to be written off and outperform.”

Disclosure: Comcast is the parent company of NBCUniversal and CNBC.