The episode starts out when two customers park at the Chum Bucket. Plankton thinks they want to eat there, but they were parked there because they couldn't find parking at the Krusty Krab. Karen then suggests that Plankton should advertise his product. Plankton then hangs a sign that reads "CHUM IS METABOLIC FUEL!" Patrick comes along and tries to read the sign, but his head starts smoking from the strain of trying to understand what these new words are. After his head is put out by a cup of kelp juice, Patrick then rearranges the letters, so the sign reads "CHUM IS FUM!" The new slogan starts to attract customers. Plankton hires Patrick as his slogan manager.
Meanwhile, back at the Krusty Krab, Mr. Krabs believes Plankton has stolen the secret formula, so he comes up with a plan to steal the recipe back. Plankton sees through SpongeBob and Mr. Krabs' disguise, and they realize that it was the slogan that brought in the customers, despite the fact the chum tastes awful. To combat the disgusting taste of the chum, the customers simply say "Chum is Fum" over and over. Then Plankton goes to Patrick to check on how his assignment to come up with new slogan ideas is going. However, all Patrick does is write Chum is Fum in a thousand different ways. Plankton then gets mad at Patrick but cools down because Patrick's slogan is still attracting customers.
A few days later, people are getting bored with the slogan, so Plankton and Patrick hold a board meeting. Patrick comes up with a new motto three days later, changing it to "FUM IS CHUM". This new slogan brings back Plankton's customers, much to the chagrin of Mr. Krabs. Business is so large that Plankton gets into the restaurant magazines and even a hockey team shows up to eat.
Patrick then decides to resign from his position as advertising director because he is "burnt out" - there is a hole burned into the back of his head. Plankton protests, but then bluffs to make Patrick believe that he is disposable, and not necessary to keep customers eating at the Chum Bucket. During his rant, Plankton accidentally insults his customers over the intercom that he had installed by the cash register earlier to taunt Mr. Krabs. His customers hear him calling them "buffoons, morons, the dumbest of the dumb" among other things, which causes all of his customers to abandon their chum in anger. Plankton then gets beaten up by the hockey team. In the end, everybody sees Patrick finishing a sign with the Krusty Krab's new slogan, "Krabby Patties are fum!" and everybody returns to the Krusty Krab.
This is the second episode where a character works for Plankton. The first was SpongeBob in "Welcome to the Chum Bucket."
This is the second episode in which Patrick helps to advertise for a restaurant in Bikini Bottom. The first was "No Hat for Pat" and the next one is "The Good Krabby Name."
This episode is, however, the only one in which he helps to advertise for the Chum Bucket.
Karen wears a hairnet even though she does not have any hair.
When the hockey players first hear Plankton talking about his customers in a bad way, there are five of them. However, when they are about to attack Plankton with their hockey sticks, there are only four of them.
The fifth hockey player may have decided not to attack Plankton.
The hockey player speaks with a Canadian accent.
This episode marks the 100th appearance of Incidental 40.
This episode is one of the few where the Chum Bucket starts to attract customers, and Mr. Krabs and SpongeBob try to steal them back, along with "Plankton's Regular" and "Greasy Buffoons."
The "Two Hours Later" time card looks just like the "Rise and Shine" title card, except the rocks are missing, and the "3 Days Later" time card looks just like the "Driven to Tears" title card, except the tire tracks are missing.
Coincidentally, both episodes use "Wahini Wobble" as the title card music, which would later be used as the title card music of this episode's sister episode.
The title card is similar to the one for "Krabby Road."
In the Indonesian dub, the first Krusty Krab scene which briefly features Squidward was skipped to for time savings reason.
In the Russian dub, when SpongeBob says "Goofy Goober has gone non-dairy?!," it is translated as "a French chef has boiled Gary?!"
The title card music is part of the instrumental version of "Oh, My Karen," which debuts in this episode's sister episode, "Single Cell Anniversary."
At the beginning of the episode, Plankton dances in a similar fashion to Dead Eye Plankton.
During the original American airing, this episode was paired with "Growth Spout."
Plankton mentions the episode's title when he says "Here's your Chum Bucket Supreme, enjoy!"
In "Patty Hype," Patrick states that he can't see his forehead, however, in this episode, he is able to do it.File:SpongeBob's Last Stand 151.pngSlogan on billboard in SpongeBob's Last Stand
The slogan "Chum is Fum" is seen again on a billboard in the episode “SpongeBob's Last Stand”.
Errors
When Mr. Krabs looks out from his office, there are only two customers, but when he says they have a situation to SpongeBob, there are no customers at the tables.
Frank has a red shirt when he approaches the counter after the Chum Bucket has a new slogan. The next shot when it zooms to the register, his shirt is blue.
The same error occurs in "Free Samples," but is pink.
When Patrick is first seen putting up the sign for the Krusty Krab, the hole in the back of his head does not appear. When Patrick appears for the last time, the hole is now on at the back of his head.
When Plankton stomps on the ripped paper in anger, his head is still messed up. However, in the next shot when Plankton yells about how he is tired of the Krusty Krab stealing his customers, his head is suddenly fixed.
At the end of the episode, when Patrick finishes the point in the exclamation mark in "KRABBY PATTIES ARE FUM!," the ladder he is stepping on is shorter, and he is below the sign. In the next scene, automatically, the ladder is longer, and he is next to the sign.