Quentin Tarantino’s “Once Upon a Time in Hollywood” exceeded box office expectations with its $41 million domestic debut, marking a career best for the filmmaker and signaling that audiences are still interested in original content with a compelling hook. Of course, it helped that it turned into a major cultural event that combined one of the world’s top directors with two of Hollywood’s biggest movie stars.

But for Sony and Tarantino, the true test for “Once Upon a Time in Hollywood” will be in its staying power. As the rare summer movie that doesn’t hail from a popular franchise and isn’t based on a comic book, the R-rated drama will have to rely on solid word of mouth to stay strong throughout the next few weekends. “Once Upon a Time in Hollywood” will launch overseas in August.

It’s promising then, that even with a B CinemaScore (his most recent hits, 2009’s “Inglourious Basterds” and 2012’s “Django Unchained,” both received an A-), “Once Upon a Time in Hollywood” was able to dominate social chatter across the country. In Los Angeles, the New Beverly and ArcLight Theaters sold out nearly every showing, as did several New York theaters. Media outlets including the Los Angeles Times took the occasion to run extensive packages exploring the history of the Manson murders, one of the principal themes of the film.

“This is certainly a mandate in favor of original content,” said Paul Dergarabedian, a senior media analyst at Comscore. “It had a lot going for it having Leonardo DiCaprio, Brad Pitt, Margot Robbie and Quentin Tarantino.”

Here are a few reasons why Tarantino packed theaters on opening weekend:

He’s selective about his projects

Tarantino has long said he will retire from directing after his 10th effort. Whether or not that happens, the filmmaker has carefully chosen the projects that make up his resume. For that reason, the release of his movies turn into events. The Vista Theater in Los Angeles encouraged guests to dress up in their best ’60s attire for the opening weekend of “Once Upon a Time in Hollywood.” After seeing the film, numerous L.A. moviegoers opted to stay in the mood and grab a bite at Casa Vega, El Coyote or Musso & Frank Grill, all locations that could be seen in the movie.

He consistently delivers

Tarantino’s selectiveness isn’t lost on audiences, who have come to associate his brand with quality. On average, the Rotten Tomatoes scores for his movies hover between 84% and 92%, an enviable benchmark for most directors. (His one outlier is “The Hateful Eight” with a 74%.) It’s become especially important in the age of streaming, where an overwhelming amount of content is available to watch anywhere, anytime with a click of a button or the flick of a cursor. Moviegoers are looking for something to rise above the noise to distinguish what theatrical releases deserve their hard-earned cash, and Tarantino has established himself as a filmmaker with a message.

For “Once Upon a Time in Hollywood,” Sony’s marketing campaign emphasized the project as “Tarantino’s ninth feature.” It paid off. Almost half of moviegoers said Tarantino’s involvement was their primary influence to see “Once Upon a Time in Hollywood,” according to PostTrak, compared to 7% for the average movie.

“Typically the director is not the primary reason that people go to see a movie,” Dergarabedian said. “That tells you Sony did a perfect job marketing it.”

Tarantino works with top collaborators in signature roles

There’s little doubt that the allure of seeing DiCaprio and Pitt share the screen for the first time enticed people to take a chance on a story set in the past with an unwieldy title. Tarantino has consistently been able to work with some of the biggest names in showbiz, giving his movies an even higher prestige. His highest grossing titles, “Django Unchained” ($450 million) and “Inglourious Basterds” ($316 million), have starred names like Pitt, DiCaprio and Jamie Foxx. Though Samuel L. Jackson was a draw, “The Hateful Eight” suffered without a buzzy cast and tapped out with $148 million globally.

He’s gaining younger fans while retaining older ones

In a promising sign, “Once Upon a Time in Hollywood” is appealing beyond its core demographic and playing younger than anticipated. The majority of ticket buyers were between the ages of 18 and 34. Its appeal was also broader than other Tarantino films, with women filmgoers seeing it as a character-driven drama rather than a non-stop gore-fest.

It pulled in big crowds on the East Coast and in Los Angeles. However, the R-rated drama also saw solid sales in the Midwest and Canada, signaling the movie had reach outside of major entertainment hubs. Momentum could continue to build if “Once Upon a Time in Hollywood” keeps generating awards buzz.