The inspiration for the film comes from the folktale "The Devil's Meeting," in which the Devil roams the earth in human form torturing the living. The film also mentions the folktale.
In its first weekend of release in the United States, the film was able to gain back its entire production budget.
The end credits do not call any of the people trapped in the elevator by their names, just their occupations or what they are, e.g. "Older Woman."
The sign on the truck that the man lands on after he jumps off the skyscraper says "Bethel bread company", Bethel is considered to be a holy place,
in the Bible it was one of the first places where the Hebrews met God.
Biblical references can be seen throughout the movie, for company names (Bethel Bread, Trinity Service Station) and places (Locust Street, Bethlehem Pike). The building number 333 can also be seen as a reference to the devil number (666) mentioned in the Bible.