The Nun was released back in 2018 to a lukewarm reception from critics, yet somehow managed to become the highest-grossing film in The Conjuring Universe. The creepy origin story of Valak the demon didn’t exactly become a hit among reviewers, and its plot, acting, and scares were deemed underwhelming or even outright disappointing. Yet, despite this, the film not only made its modest $22 million budget back but skyrocketed at the box office to become the Conjurverse’s biggest weekend opener. Today, nearly three years later, it remains the most financially successful film to come out of the entire franchise. But why is this the case for the underwhelming entry?

When The Nun released in September of 2018, no one could’ve predicted how massively successful the film would be. The creepy prequel to the original The Conjuring was produced on a small enough budget that its financial success was practically guaranteed, but when the film blew past industry expectations to gross $365.6 million worldwide, everyone from audiences and critics to theaters and Warner Bros. themselves were surprised.

Related: The Conjuring Universe Complete Timeline

All of this begs the question: why did The Nun defy the critics to become such an overwhelming financial success? Audiences kept coming to the theater to see it, and there were clear factors contributing to its status as the highest-grossing Conjerverse entry. According to a deep analysis (via Business Insider), the answers to these questions can be found by taking a look at several big factors: the cinema landscape of late 2018, the marketing surrounding the film, and The Nun’s international appeal.

The Nun Conjuring 2 Spin-Off

The first big reason why The Nun performed so well was due to the relative scarcity of horror movies playing in theaters during 2018. The year was light on genre offerings, with two of the only other notable examples being The First Purge and Slenderman. Neither of those films was particularly enticing to audiences, making horror movie fans hungry for new content. As a result, when The Nun opened, fans of scary cinema arrived at theaters in droves, with friend groups comprising a significant number of ticket sales.

This explanation also feeds into the second big reason for the film’s success; its aggressive marketing campaign. The trailer for The Nun became a mega-hit on YouTube, and horror aficionados couldn’t wait to finally see the film itself. Of course, The Nun’s connection to the Conjurverse was also a big draw, and the promise of a backstory for the demonic antagonist of The Conjuring 2 definitely piqued the interest of the franchise’s fans.

The third and final major factor in The Nun’s success is undoubtedly its international appeal. While large film markets like China don’t often provide big returns on Hollywood horror movies, South American and Spanish-speaking countries are traditionally solid markets for the genre. The Nun’s lead star was Mexican actor Demián Bichir, and it’s no coincidence that the film’s strongest foreign opening weekend was in Mexico. When this international success is combined with its pervasive marketing and its presence in a horror-starved year, it’s obvious why The Nun emerged as a box office winner in 2018. It remains to be seen if any new additions to The Conjuring sequels or spinoffs will one day replace it in the top spot.

Next: The Nun 2 Updates: Is The Conjurverse Sequel Happening?