Trope Namer: The Red Stapler — for the situation where a movie affects or creates a Real Life demand for an object, good or service. Swingline didn't make them when the movie was produced, but does now.
Vindicated by Cable: One of the premier examples. The movie pulled in mediocre box office numbers, despite relatively good reviews from critics, but found a second life on premium cable and on home video. Comedy Central's frequent airings brought the movie to an even wider audience, quickly granting it Cult Classic status.
What Could Have Been: After the first film's success on video and becoming a Cult Classic, Mike Judge was offered the opportunity to make a sequel to the film. But making the first film was such an unpleasant experience for him that he declined.