In Episode 71, the seating of the extra dolls on the airplane varies from scene to scene.
In Episode 80, Deandra claims that she did not look to her left... when in fact she needed to look to her right side.
Christmas Rushed: A literal examplenote Season 4 premiered January 2015.; in a livestream on the MPGiS app, the creators admitted that latter half of the more-maligned Season 4 was written in one night.
Colbert Bump: Sales and reviews for certain Barbie dolls surged (the ones MPGiS use) after some people watched the show.
There have been several WMGs regarding Deandra's secret for leaving Atchison High. Most of which that were included was her, pooping all over the place in the middle of a cheer routine and they were spot on!
Throw It In!: Since most of the cast is experienced with improv, a lot of the lines in the series aren't in the script. In the Behind the Scenes video, the creators have stated that some of the funniest lines were made up on the spot.
Special mention goes to Bridget Tice's dialogue. Pretty much all of her lines were made up by the actress.
The famous scene from season 1 that is being dubbed the "Trisha monologue" is improvised as well. And what we heard was only a portion of the full speech Garrett (Trisha's VA) made up.
Trisha was supposed to be voiced by a girl when they were creating their very first video, but her actress didn't show up. So they settled for one of the guys to do her voice. Of course, due to the current state of things, nobody would want it in any other way.
MPGIS wasn't originally supposed to be a serialized show with a bunch of episodes, just an anthology series focusing on "The Most Popular X in School". Episode One was just called "Bathroom Hierarchy".
Mikayla was originally not a Van Buren.
Jenna Darabond and Jenna Dapananian would've showed up in Episode 5.
Deandra was originally going to be hailed as some sort of prophet, as in to save Overland Park, and humanity.