the article in Malcolm Gladwell's "The Tipping Point" regarding the Pepsi Challenge is pretty awesome. Or was it in "Blink?"
Though, it's more related to the disaster of "New Coke." Coca Cola's failure to realize that what people prefer for tasting--basically, the sip performed in these taste tests--is in no way related to what people will continue to drink, as in a full 12oz beverage.
People preferred to sip Pepsi b/c it is very much sweeter, but that gets to be too much for a full beverage. Brilliant marketing by Pepsi, and Coke simply failed to see this difference, panicked, and spent millions on ver-hauling their business, nearly driving themselves into bankruptcy with the disaster that was New Coke. They eventually noticed that The Pepsi Challenge never actually translated to increased sales of Pepsi, but when they brought in New Coke, their own sales plummeted.