Most viewed movie trailers in their first 24 hours as of September 2021

As of September 2021, "Spider-Man: No Way Home" – set to be released in December that year – was the most-watched movie trailer 24 hours after its release, with over 355 million views. "Avengers: Endgame" (2019) followed with its teaser trailer recording 289 million views during its first 24 hours and its final trailer having 268 million views on its first day. This film was also Marvel Comics' biggest box office revenue worldwide.

The economics of movie trailers

To release a movie trailer online is a recurring means of introducing an upcoming production to a broad audience. In the second quarter of 2021, social media and ads on over-the-top (OTT) services were among the most common ways of discovering new films in the United States and Canada. Still, television remains an important medium for teasers and final trailers. In early 2020, studios spent millions of U.S. dollars on movie commercials on American TV.

Fandoms of films: online and ongoing

Launching movie trailers online may also boost the conversation about them across the internet. As of January 2020 – just before the COVID-19 outbreak – nearly seven out of ten internet users aged between 18 and 44 years in the U.S. watched or streamed movies at least once a week. Those more passionate about certain films continue to talk about them online even years after their theatrical releases. As of June 2021, the Harry Potter franchise and "Titanic" had about 77 million and 53 million Facebook fans, respectively.