Measuring the impact of promotion on sales of healthier, more sustainable foods

What? 

Tesco has set ambitious targets to drive up sales of healthier, more sustainable products by 2025 to help support customers to eat a more balanced diet. Interventions to nudge customers towards healthier options will be essential to meeting these targets. During 2021, Tesco conducted three separate trials to test the impact of targeted promotional activities on the purchase of fruit and selected healthier alternatives.   

How?

For the first time Tesco ran a large-scale Veganuary promotion in 96 stores to encourage purchasing of plant-based food during January.  The second trial aimed to influence customers to buy more seasonal summer fruit, running for 16 weeks in 100 stores, with another 100 stores used to provide control data. While the third focused on promotion of no added sugar plant-based milks in 200 stores during a three-week campaign.  

All interventions were price promotion and prominent positioning interventions, using a mix of techniques including targeted messaging on banners and aisle fins, tailored social media activity and in store tastings, to encourage people to buy specific healthy products. 

Data and results

Tesco provided aggregate data on sales (£) and units in selected stores between 2018 and 2021, which was independently analysed by a team at the University of Oxford. Data showed: 

1. Sales of seasonal fruit increased by 22% across both the intervention and control group stores during the period of promotional activity. Higher sales across the board could be due to increased space given to seasonal fruit during this period.  

There was no clear evidence that the seasonal fruit promotion had an impact on sales of the wider fruit category, suggesting customers switched to seasonal fruit rather than increasing the amount of fruit they bought overall.  

2. Unit sales of the no added sugar plant-based milks targeted in the promotions were 2.9 times higher on average per store per week during the promotional period, compared to the previous period. The activity also impacted on sales of other plant-based milks while the promotion was running – unit sales of no added sugar products not included in the promotion were 1.5 times higher and sales of all plant-based milks were 1.3 times higher, compared to the previous period.  

Data suggests the promotional activity did encourage additional purchasing of plant-based milks and particularly of no added sugar products. However, these uplifts were short-lived, with sales returning to baseline after the trial, meaning the impact was not sustained.