The reformulation of the original less sweet, more bitter Coca-Cola (now Coca-Cola Classic) into a new sweeter one (eventually called New Coke) was one of the biggest decisions in the firm's history. Coke was responding to Pepsi's gain in market share with its sweeter formulation and its Pepsi Challenge taste tests and commercials. New Coke replaced "old Coke" on supermarket shelves. Loyal Coke customers were incensed that "old Coke" was discontinued. They loved the taste and brand identity of "old Coke" and rebelled against New Coke. TV and print ads designed to persuade Coke and Pepsi drinkers to switch to New Coke were ineffective. After a short period of time, Coca-Cola reintroduced old Coke as Coca-Cola Classic and withdrew New Coke from the market. The launch of New Coke is an example of .