Wikisimpsons - The Simpsons Wiki
The Kwik-E-Mart isn't all that convenient of a store with Apu gouging the customers for all they've got. It sells the standard convenience store fare at extraordinarily high prices, such as milk for $12, "surprisingly expensive penny candy" or Valentine's Day chocolates for $100 and including the always popular tasty frozen soft drink Squishee. Once during a holdup, Apu refused to give Homer change to call the police from a payphone. Instead, Apu directed Homer to the cheapest item in the store: a 6 oz bag of Chippos potato chips at $5.99. (To which Homer whispered shouts of "$5.99?! Someone should shoot you!")
The Kwik-E-Mart has also been known to sell faulty, dirty and expired merchandise, though legal to sell items that have been damaged or close to expiration, it is illegal to sell it if it has already expired, especially if you don't tell the customer it is as such, like Apu. It is also so notorious for its daily robberies by Snake Jailbird.
The Kwik-E-Mart chain was started somewhere in the Himalayas, where the world's first convenience store still stands on a mountain peak, an ironically inconvenient location. Visiting pilgrims are allowed to ask three questions of the resident all-knowing guru (except safe combinations). Apu's visit was spoiled by Homer's three questions, "Are you really the head of the Kwik-E-Mart?", "Really?" and "You?" The guru answered "yes" to all three of Homer's questions, and refused to answer any of Apu's, instead saying, "Thank you, come again." 
Apu was fired from his job by Kwik-E-Mart HQ after Homer Simpson contracted food poisoning from the Kwik-E-Mart's spoiled meat and failing to "blame [it] on a scapegoat or sacrificial lamb." Apu was replaced by actor James Woods who was studying to be a convenience store clerk for a role in an upcoming movie. Apu was re-hired a short time later, after he foiled a robbery attempt at the Kwik-E-Mart and saved James Woods' life. Apu was shot during the attempted robbery. Apu has also stated that the parent corporation of his store is "Nordine Defence Dynamics," when he is commenting on the prosecution of Marge for shoplifting. Apu has been suggested as the owner of his own Kwik-E-Mart.
Apu is hailed as a legend in the realm of Kwik-E-Mart employment for once working a shift for over ninety-six hours. During the shift he experienced a hallucination in which he thought he was a hummingbird and tried to drink nectar out of his brother Sanjay's head.
Apu once installed sixteen gas pumps in the parking lot on the Kwik-E-Mart to compete with a rival store, the Gas'N'Gulp. However, a round of redirected mortar shells from Fort Springfield promptly ruined his hard work. The store itself also appeared to be destroyed: the "K" in the store's name landed on the fort grounds moments later. However, a later episode showed gas pumps at the Kwik-E-Mart.
The Kwik-E-Mart has not been immune to the concept of showmanship as a marketing technique. When retiree Jasper Beardley decided to freeze himself in the store's freezers as a low budget form of cryopreservation for an indefinite future, Apu transformed the store into the "Freak-E-Mart", of which Jasper, marketed as "Frostillicus", was the main attraction. When Jasper thawed, thus ending the viability of the project, Apu decided to institute a clothing optional policy, briefly rechristening the store as the "Nude-E-Mart".
The Kwik-E-Mart also includes a Utopian garden on its roof; Paul and Linda McCartney often relax there. The garden is accessed through the refrigerator labeled "Non-Alcoholic Beer". When Lisa asks what Apu does when somebody wants to purchase some, he replies, "You know, it's never come up." In accordance with Apu's vegetarian philosophy, all hot dogs at the Kwik-E-Mart are actually made of tofu. No customer, Apu claims, has ever noticed any difference. Although given the average Springfielder they would most likely react violently if they were told.
Despite generally being a good-natured and friendly individual, Apu often exhibits a ruthless, capitalist streak. He has caressed his cigarette machine in gratitude for not dispensing its products after taking a customer's money. His catchphrase after a purchase is always, "Thank you, come again!" Even after dealing with a difficult customer—Homer—he states, "Please pay for your purchases and get out and come again!"
After the town of Springfield fined Mr. Burns $3 million for illegally dumping toxic waste, a town meeting was held to discuss how to spend it. Apu suggested spending some of it on hiring more police officers, as he had been shot eight times that year and nearly missed work. Chief Wiggum responded, "Crybaby."
 The Simpsons: Hit & Run
The Kwik-E-Mart can be found near the first Lard Lad's, Gas Station and Krusty Burger. In Level 1 you can purchase "Character Clothing" at the store. It also has one Buzz Cola vending machine to get coins.
In Level 7 of Hit & Run Springfield has transformed into a creepy city full of witches, ghosts and zombies everywhere. All of the buildings and houses have been transformed into Halloween places, with pumpkins at the entrances and on the streets was the name of the store "Spook-E-Mart".
 The Simpsons: Tapped Out
In some Episodes When the Kwik E Mart is shown a Dog's Howl Can be Heard Similar to the Crow's Caw at the SNPP the Kwik-E-Mart headquarters is based somewhere in the Himalayian mountains.
 Behind the Laughter
In 2007, as an advertisement for The Simpsons Movie, selected 7-Eleven stores in the United States and one store in Canada were temporarily converted into Kwik-E-Mart stores. During the promotion they sold: Buzz Cola, Krusty-O's cereal, Simpsons donuts, Squishee cups, etc.
Also, a real Kwik-E-Mart store (though using completely different signage) exists in the downtown area of Pittsburgh, Pennsylvania.