Kevin Smith worked in the store where they shot the film. They shot for 21 straight nights. He would clock in at 6am and finish at 11pm. They would then shoot till 4am, after which he would try to grab an hour or two's sleep before getting ready to go back to work.
Kevin Smith, a keen comic book fan, sold a large part of his collection to help fund this film. He has since been able to buy most of them back.
Filmed at the same store in which director Kevin Smith was working at the time. As he was only allowed to film outside of business hours, and because bright enough lights couldn't be afforded, the plot included an explanation for the shutters always being down.
Jason Reitman has said that this film inspired his desire to be a filmmaker. Reitman later told Kevin Smith this, which lead Smith to jokingly quip, "You're the son of Ivan Reitman. You grew up on the sets of Los cazafantasmas (1984), and El pelotón chiflado (1981). It took ME to let you know that you can be a director?"
Kevin Smith: [Star Wars] There are multiple conversations and references to the Star Wars films including, but not limited to, Randal's discussion about the end of Return of the Jedi and the song about Chewbacca.
Kevin Smith: [37] A recurring number in many of Kevin Smith's films, 37 originated in this film as the number of guys Dante's girlfriend, Veronica, has fellated.
Kevin Smith: [Jaws] (at around 1h 16 mins) After the fiasco involving Caitlin and the dead guy in the bathroom, Randal is pulling a chip through a jar of salsa saying "we're gonna need a bigger boat..." alluding to Tiburón (1975), one of Smith's favorite movies.