The British wing of Schweppes has increased its soft drinks sales in Britain by developing an under utilised partnership: alcohol.

The soft drink manufacturer has been teaming up with liquor brand Diageo to market combined deals on soft drinks and liquor.

The partnership was launched in the UK in 2010 after Schweppes realised it needed to do more to increase its fizzy drink sales among adult British shoppers.

It decided to target liquor buyers after realising they rarely bought gin, vodka or other spirits without also purchasing a soft drink mixer.

The challenge for the market is that Britons notoriously prefer wine and beer, according to a case study on the big brand partnership published by the Path To Purchase Institute.

“Because spirits are comparatively expensive, consumers are reluctant to spend more and take the risk that their bartending skills will fall short.”

The solution was a supermarket campaign that teams Schweppes soft drinks and Diageo spirits together in one easy and affordable package.

The ongoing “Perfect Partners” promotion features the headline “together for a better summer” and is marketed during the warmer British months.

Shoppers are offered a £10 deal on a bottle of soft drink and liquor, and typical mixes are merchandised together, such as gin and tonic, ginger ale and vodka, or Pimm’s with lemonade.

Supermarket chains Sainsbury’s, Tesco, ASDA, and Morrisons get involved in campaign, which is now in its fourth year.

The partnership has led to a “continual increase in cross basket spending and frequency of light shoppers,” says the case study.