Answer: Coke

There are few food marketing gaffs that can even begin to compare with the Coca-Cola Corporation’s attempt at introducing a new formula in 1985. Dubbed “New Coke”, it was a massive marketing and rebranding failure. Although many testers and members of the general public said they actually preferred the new formulation over the old one, Coke simply had too many diehard fans to pull such a radical move.

Despite being well received by a significant minority, it was poorly received by the market majority. Coke’s corporate hotline received around 1,500 angry calls a day and executives, scrambling to make sense of the public reaction, even hired a psychiatrist to listen to some of the wildly irate phone calls. When the psychiatrist reported back to the executive board, he noted that many of the callers were responding with a level of grief and emotional reaction typically reserved for the death of a loved one.

Given how strongly the public responded to the new formulation, it’s no surprise then that the reintroduction of the original formula (a short three months later) was considered breaking news. ABC News anchor Peter Jennings interrupted the afternoon’s episode of General Hospital to break the news to viewers. U.S. Senator David Pryor announced the reintroduction of the old Coke formula on the Senate floor. Most telling, however, was that the same Coke hotline that had been inundated with 1,500 angry calls a day received over 30,000 calls in a two day window praising the company for returning to the old formula.

Although “New Coke” is trumpeted as the biggest marketing failure of the 20th century, when viewed through the lens of the ensuing decades, it may just have been the most (accidentally) brilliant marketing decision of all time. After the whole fallout and the reintroduction of the original Coke’s formula, sales figures skyrocketed to double that of their competitor Pepsi, and people were even more fiercely loyal to the brand as they’d experienced what it was like to go without it.