According to the data, all supermarket brands enjoy positive WOM: on average, conversations about food retailers are 64% positive and 6% negative.

However, there is wide variation across the sector: 81% of Aldi’s WOM is positive, while just 58% of Tesco’s is positive.

“Contrary to some perceptions, all the major UK supermarket brands are discussed positively in everyday conversation,” said Steve Thomson, managing director of Keller Fay. “But the star performers in the sector enjoy a significant lead over the big four brands, and this powerful brand advocacy is clearly reflected in their stronger sales performance”.

Full rankings of positive WOM are as follows:

Aldi: 81%

Lidl: 78%

Waitrose: 77%

ASDA: 66%

Morrisons: 64%

Sainsbury’s: 63%

Tesco: 58%