In the early 1980s, Pepsi Cola did some surveys that discovered in blind taste tests, people preferred the taste of Pepsi Cola over Coca-Cola. So, Pepsi started advertising this, where it showed TV ads where Pepsi and Coke side-by-side behind a box, and the customers were asked which they liked better, and no surprise, they chose Pepsi. These ads were run under the name The Pepsi Challenge. Unsurprisingly, Coke started to lose market share to Pepsi.
The Coca-Cola Company didn't like either of these, so they tried making fun of Pepsi's ads by having people do taste tests of tennis balls! And other supposed parodies of Pepsi's ads, by claiming that one taste was not enough to decide (that the other product was better). This play of dueling advertisements and subsequent events became known as the "Cola Wars."
That probably didn't work either, so Coke decided that if they can't beat them they'd join them. Coke changed its formula to make it sweeter and thus more like Pepsi. They called it "New Coke." They probably would have been better naming it "New Edsel," because the campaign bombed. It was like touching an inflamed nerve on an infected tooth. Coke started to lose even more market share as a lot of people got very pissed that their beloved soft drink had been altered.
Well, the people at Coke are not stupid, so they announced they would be returning the original formula as "Classic Coke." They kept the changed formula around as "New Coke" until the furor died down, then quietly retired it. About 20 years after the fiasco, Coca-Cola felt it was safe to drop "classic" from the name, and so things are back the way they were before this happened.
As a result of this, the term "Pepsi Challenge" entered the lexicon as a straight comparison between competing products.
- In Pulp Fiction, the drug dealer who sells heroin to Jules says that his stuff is much better than some of the other stuff being sold, and he'll accept a Pepsi Challenge for his smack over anyone else's