But in the 1980s, carbonated soft drinks overtook tap as the most popular drink, with Coca-Cola and PepsiCo putting their marketing muscle behind their colas with celebrity endorsements from the likes of pop star Michael Jackson and comedian Bill Cosby.

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First news hit the markets that for the first time ever, Diet Coke had overtaken Pepsi as the second-most popular soft drink in the country, behind Coca-Cola.

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Pepsi, the flagship brand of PepsiCo, is the second most popular soft drink brand worldwide and trails only Coca-Cola in terms of sales.

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The most iconic example is the Coca-Cola Company's attempt to reformulate the world's most popular soft drink on April 23, 1985 - "a day that will live in marketing infamy", according to the company's website.

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