Diageo is putting £1.5m into the latest execution of its highly successful Win-a-Diamond campaign for Smirnoff.

The promotion first ran last year and saw one major retailer experience a sales increase of almost 20% - equivalent to an extra £15,000 a week.

The new off-trade campaign, which runs through April and May, once again targets female shoppers with the chance to win one of hundreds of diamonds the brand is giving away.

It will be backed with national press and digital advertising as well as point-of-sale material and in-store sampling activity.

The company is also launching a TV advertising campaign to highlight the promotion, which begins on 25 April. "The advertisement highlights the lengths we go to make the ultimate vodka and compares that with the process used to create a pure diamond," explained Anita Robinson, Smirnoff marketing director, Diageo.

"A promotion such as Diamonds will offer a way to boost Smirnoff volumes at a good margin and drive value back into vodka," she added.

The 70cl and one-litre promotional bottles will feature a "unique wet and reveal mechanic", said Robinson.

"There will be a booklet on the neck collar, which will feature a droplet that consumers will have to wet in order to reveal if they have won or not."

Smirnoff is the number-one vodka brand in the UK off-trade with sales of more than £650m [Nielsen MAT to 27 January 2007].