!!The book:
* GeniusBonus:
** Patrick gives detailed descriptions of each character's clothes, including brand names and prices. Readers who are extremely knowledgeable about 80's fashion will notice that the outfits are clownishly mismatched.
** There's a similar gag involving the food at the various restaurants, which go from outrageous but plausible (red snapper pizza) to outright inedible (mud soup and charcoal arugula).
* TechnologyMarchesOn: Patrick's state-of-the-art home entertainment toys seem a bit quaint when read now.
* WriteWhoYouKnow: Ellis has described Bateman as being based on his father.

!!The film:
* ActorSharedBackground: Patrick once justifies his assumption that Elizabeth is a lesbian by reminding her that she went to Sarah Lawrence. Creator/GuinevereTurner (who plays Elizabeth) '''is''' a lesbian, and really '''did''' go to Sarah Lawrence.
* CreatorCameo: Elizabeth, Patrick's very drunk (supposed) friend, who has a threesome with him and Christie in his apartment [[spoiler: and who he kills, shortly before killing Christie herself]], is played by the film's co-screenwriter, Guinevere Turner.
* DyeingForYourArt: Christian Bale worked out constantly to achieve the buff, narcissistic look a person like Bateman would have.
* FakeAmerican: Creator/ChristianBale, a Wel-''[[InsistentTerminology English]]'' actor, played Patrick Bateman in the film.
* TechnologyMarchesOn: In the movie, the most visible example is the ''gigantic cellphone''.
* VisibleBoomMic: One casts a reflection off of a CD case in Bateman's office during his 2nd meeting with Detective Kimball.
* WhatCouldHaveBeen:
** Creator/LeonardoDiCaprio was the original actor for Bateman before he had to drop out due to schedule conflicts. Imagine what THAT would've been like.
** Creator/EdwardNorton and Creator/BradPitt were also initially offered the role.
** At least three screenplays were written: one by Matthew Markwalder, one by Mary Harron and Guinevere Turner, and one by Creator/BretEastonEllis himself. Harron and Turner's script is what ended up in production.

!!The musical:
* FontAnachronism: The business card scene and song number includes a reference to "Comic Sans", which was released 1994 and wasn't around at the time of the events in the musical, taking place in the late 1980's.
* PlayingAgainstType: Creator/MattSmith as Patrick Bateman.