Cadbury Schweppes is flooding the American market - with 250 million free cans of Diet Dr Pepper.
The drink with the top secret recipe is being given away at thousands of stores across the US in what is thought to be the biggest product sampling exercise ever.
And in an unusual touch the company will send free drink coupons to everyone with the last name Pepper.
"We think it's the biggest sampling programme in history," said Andrew Springate, vice-president for Dr Pepper brand marketing at Cadbury Schweppes .
"We have not found anything even remotely close."
Extensive sampling programmes are typically used to introduce new products, or pump up failing ones, but Diet Dr Pepper is in neither category.
Cadbury Schweppes said sales for the brand were up 15 per cent last year, building on a 16 per cent increase in 2004.
The drink currently holds a three per cent market share.
Mr Springate said: "We have had year-over-year volume growth in double-digits for more than a decade."
The parent company has enjoyed an upswing in recent years.
For 2004, its US market share in the soft drink category rose slightly to 14.5 per cent while the far larger Coca-Cola and Pepsi saw their shares slip to 43.1 per cent and 31.7 per cent respectively.
An advertisement campaign that stresses taste, comparing Dr Pepper to a rich dessert, began in January.