One day, Mr. Krabs is shown looking through a telescope on the top of the Krusty Krab, spying on customers and taking pictures of any Bikini Bottom residents. He then enters the restaurant and calls SpongeBob and Squidward into his office. He shows them the pictures of the customers and asks SpongeBob if he has seen any of them inside the Krusty Krab. They both answer in the negative and Mr. Krabs then tells SpongeBob and Squidward that twp percent of the residents of Bikini Bottom have not set foot in the Krusty Krab, which means that two percent of money is not being earned. He tells them that he wants them to go out and promote the restaurant, but only SpongeBob is willing while Squidward stays at the Krusty Krab.
The next scene, SpongeBob is shown coming out of a giant hole at the top of the Krusty Krab wearing a Krabby Patty costume and jumping off of a giant spatula. He asks a random fish if he has heard of the Krusty Krab, and he tells SpongeBob that he is just about to enter the restaurant. The man takes flyers that SpongeBob is offering about the Krusty Krab and leaves. Patrick is then shown watching SpongeBob, whom he believes to be evidence of the "invasion of the giant patties" from behind a giant rock. He then lunges out at his friend and tries to eat him. When SpongeBob tells him that he is inside the costume, Patrick thinks that the patty ate SpongeBob and continues to attack him, and launches him into the air. The costume lands on top of Plankton, who is about to go to the Krusty Krab to attempt to steal the Krabby Patty formula. Patrick makes sure that SpongeBob is okay, and SpongeBob tells him of his job to promote the Krusty Krab. Patrick tells SpongeBob that he needs an even bigger advertisement blitz.
Patrick has then shown shaving the message "Eat at the Krusty Krab" on SpongeBob's back, and painting the message on the walls with black paint. SpongeBob is then used to stamp the message all over downtown. A cop walks by and considers arresting them for graffiti, but then decides to go get a Krabby Patty instead. Patrick tells SpongeBob that he had hired a skywriter, but the skywriter falls out of the plane, holding a clipboard that says "Help me", and crashes onto the edge of a cliff. A scout leader and three campers are then shown, on a tour of the oldest tree in Bikini Bottom. However, the tree falls over when Patrick creates the advertisement out of its leaves.
SpongeBob is then shown exiting a bathroom stall and telling a man that they had left a present for him. The man walks into the stall and sees that "Eat at the Krusty Krab" is written on every sheet of toilet paper. Patrick is then shown flying a plane with a banner advertisement in back, and SpongeBob is shown flying a blimp. Patrick almost crashes into SpongeBob, but somehow the blimp avoids the plane. They soon collide, however, and both fall to the ground, screaming. Pilar expresses that if he sees the words "Krusty Krab" one more time, he will scream. When the blimp and plane both crash in front of him, and he sees that it says "Krusty Krab", he screams and causes SpongeBob's and Patrick's skins to change places.
Suddenly, a cellphone is heard ringing inside of Patrick's pocket, and it turns out to be Mr. Krabs, calling them and telling them that their advertisement campaign is working well, and that the Krusty Krab is packed, as well as that some of the customers who had never previously entered the restaurant are now there. Squidward is shown cooking the patties as well as taking many orders. Mr. Krabs tells SpongeBob and Patrick to continue doing what they have been doing and to try to find the last 1 percent, which they are unsure of how to find. They realize that they did not advertise over a highway of boats, and go there. Patrick turns into a traffic cone and makes a truck stop, and "Eat at the Krusty Krab" is then painted on the truck's side by SpongeBob.
After causing a massive crash, the two then go back to the Krusty Krab to tell to Mr. Krabs they made it, and the crashed cars' drivers are seen charging into the Krusty Krab. He and Patrick tried their best to hold the door, but Mr. Krabs welcomes them in.
As the customers were breaking the Krusty Krab, Mr. Krabs grabs one of the last customers and brings him to the top of Krusty Krab to give him a Krabby Patty. He voices his approval of the campaign and the Krusty Krab completely collapses right after.
When this premiered, at the end of the episode, the credits showed the cast for "The Good Krabby Name" and "Move It or Lose It" instead of "Squid Baby" and "The Good Krabby Name."
Though, this might be because "Squid Baby" is a Season 9 episode.
Patrick refers to a previous episode, "To Save a Squirrel," from Season 5. When he said 'I know what to do, It's Eat Or Be Eaten'. This is the second episode in the series to reference a past episode. The first time was in "Whelk Attack," when SpongeBob said he had the suds, which is a reference to the episode, "Suds."
In several past episodes it is stated that everyone in Bikini Bottom has eaten at the Krusty Krab at least once meaning this episode has been in a past time.
If 2% of the population did set foot in the Krusty Krab, and 12 people was 2%, then that means there must be at least 600 people in Bikini Bottom by now. The population must have increased or decreased by 62 before/after "What Ever Happened to SpongeBob?" because the population in that episode was 538.