The popularity of movie trailers on YouTube acts as a strong indicator for the worldwide gross box office income for a movie. Looking at over 3,500 movie trailers on YouTube for the top 100 grossing movies of 2019 (as of September 2019), there is a strong positive correlation (R²=0.87) between the number of video views and worldwide gross box office income. 

Taking the relationship as predictive would suggest that current releases like Joker (279m trailer views) will achieve a box office return of $990m (currently at ~$750m after four weeks of release); whilst, looking ahead, Terminator: Dark Fate has 125m trailer views, suggesting a box office return of $380m could be likely (for context, Terminator: Genisys made $440m, and Terminator: Salvation made $371m). 

But the critical appeal of a movie also has an impact once released. Titles such as Captain Marvel or Alita: Battle Angel which over-perform based on what the trailer-interest relationship would otherwise predict, tend to have a higher Ampere Critical Rating, indicating that word-of-mouth and critical review have driven up box office demand. By contrast, titles that under-perform box office expectations based on this relationship, such as Fast & Furious: Hobbs & Shaw or X-Men: Dark Phoenix tend to have far lower critical ratings, indicating that potentially interested consumers have been put off by reports of the movie’s quality. These latter cases can see a film make as little as 50% of the box office revenues that early trailer views would suggest it could make; indicating that content quality can potentially halve the income of a hyped title.