Displaying an International Wine Challenge (IWC) seal of approval increases sales of a wine by around 15%, two studies have found.

The IWC conducted studies in Marks & Spencer and Morrisons to test the impact on consumer behaviour of displaying its stickers on wine bottles. The stickers were applied to more than 100 gold, silver and bronze medal winning wines during the four week studies.

M&S, IWC’s supermarket of the year, saw a 20% sales uplift on the stickered bottles, compared to control stores with similar demographics which did not use the stickers. Morrisons saw a boost of around 10% for its stickered wines.

Both retailers already use the IWC logo on their POS materials, but the IWC said the studies showed that the medal stickers had a much more powerful impact on buying behaviour.

“The study has shown that highlighting the medal winners in store helped customers to make informed purchase decisions and confidently broaden their buying choices, said Garry Brooking, M&S trading manager for wine. “We are now looking to roll this initiative out to all of our stores.”

“The most exciting finding from the trial was evidence that highlighting the awards gave our customers the confidence to spend a little more per bottle and try different medal winning wines,” said Mark Jarman, head of wine operations at Morrisons. “This is a great endorsement of the IWC and provides compelling rationale for stickering award winning wines at source.”

The IWC, now in its 32nd year, is owned by The Grocer’s publisher, William Reed Business Media.