The pilot was shot in a functioning K-Mart during operating hours. Customers would approach the cast and crew to ask them which aisles certain items were in between scenes. That particular K-Mart has since closed permananty.
A running joke is that the actor who plays Jonah looks like Scott Baio. Scott Baio starred as Charles from Charles in Charge and homage was paid to this in episode 4 from Season 2 when Jonah dared Amy to sing the theme song from Charles in Charge.
In I Feel Bad: I Need My Mom (2018), Emet and David go to Cloud 9 to buy presents to win the nanny back. This now puts I Feel Bad and Superstore in the same fictional universe. However, this also creates a unique situation. Johnny Pemberton plays two different characters in both shows; Bo in Superstore (2015) and Griff in I Feel Bad (2018). As such, both characters now exist in the same universe.
The trivia items below may give away important plot points.
Amy's (America Ferrera's) name tag is different in every episode. She stated in the first episode that she does not like strangers calling her by her name. Except for episode 11 where she becomes assistant manager and her name tag finally says "Amy."
During the "Spring Cleaning" episode, Eugene is seen cleaning graffiti off of a bathroom stall. The graffiti reads "Bo", indicating that new employee and father to Cheyenne's child was the one who did the grafitti.
In Season 3, Episode 5, "Sal's Dead," Sean Whalen's character Sal Kazlauskas is found dead behind the drywall at the Cloud 9 store. In 1991, Sean Whalen played the character Roach in the movie "The People Under the Stairs" in which he was confined to live under the stairs and in the walls by his adoptive parents.