What is a sleeper film?

A sleeper film is a film that is unexpectedly successful despite having no big-name actors or a big-budget marketing campaign. Sleeper films often appeal to niche audiences passionate about a particular subject or style of filmmaking. These films often gain attention through word-of-mouth recommendations, positive reviews from critics, or online buzz. Some examples of sleeper films include "Napoleon Dynamite" (2004), "The Blair Witch Project" (1999), and "Get Out" (2017).