In-store placement promotions are used widely in supermarkets, but their effects on customer purchases remain largely unknown. This study examined associations of supermarket placement promotions with customer purchases overall and by Supplemental Nutrition Assistance Program (SNAP) benefit use.
Data on in-store promotions (e.g., endcaps, checkout displays) and transactions (n=274,118,338) were obtained from a New England supermarket chain with 179 stores from 2016-2017. Product-level analyses examined multivariable-adjusted changes in products' sales when they were promoted (versus not) across all transactions and stratified by whether the transaction was paid for with SNAP. Food group-level analyses examined the extent to which a 20% increase from the mean number of weekly promotions for a food group (e.g., increasing the number of candy promotions from 17.0 to 20.4) was associated with total food group sales. Analyses were conducted in 2022.
Across stores, the mean (SD) number of promotions per week was highest for sweet/salty snacks (126.3 [22.6]), baked goods (67.5 [18.4]), and sugar-sweetened beverages (48.6 [13.8]), and lowest for beans (5.0 [2.6]) and fruits (6.6 [3.3]). Product sales were between 16% (low-calorie drinks) to 136% (candy) higher when promoted (versus not promoted). In 14 of 15 food groups, associations were stronger among SNAP versus non-SNAP transactions. The number of in-store promotions was generally not associated with total food group sales.
In-store promotions, which were mostly for unhealthy foods, were associated with large product sales increases, particularly among SNAP purchasers. Policies limiting unhealthy in-store promotions and incentivizing healthy promotions should be explored.