Shoppers exposed to digital advertisements inside stores were more likely to buy the featured products, according to research covering 237 campaigns and about 30 million shopping journeys.
The study, published in the Journal of Marketing, found an average increase of 8.1% in the likelihood of buying an advertised product. That is a relative increase, not an 8.1 percentage-point increase.
The findings offer retailers and brands evidence about a fast-growing advertising channel, but they do not mean every screen or campaign will produce the same return.
What the researchers measured
Dennis Herhausen, David de Jong and Dhruv Grewal studied campaigns displayed on screens inside grocery stores. Their analysis compared product purchases by shoppers exposed to an advertisement with those of shoppers who did not see it.
For illustration, if 10 out of 100 shoppers in a comparison group bought an item, an 8.1% relative increase would correspond to about 10.8 out of 100. That example explains the calculation; it is not the study’s reported baseline.
Advertising campaigns varied by product and message, giving the researchers an opportunity to look beyond a single promotion. The authors also examined potential differences in exposure, including the possibility that people who spent longer shopping were more likely to encounter a screen.
Placement and context mattered
The reported effect was stronger when a screen was closer to the advertised product. It was also larger for novel, lower-priced and popular-brand products, and for products associated with enjoyment rather than practical needs.
Results varied with conditions including the day, time, store traffic and whether another promotional cue was present. Those patterns are useful for designing tests, but they do not establish that moving a screen or changing a message will always improve a campaign.
The researchers also found that advertising was associated with sales of other products from the same brand and category. They did not find that customers who bought the featured products spent more on them, unlike in the comparison with price promotions.
Sales need to cover the cost
For a retailer selling advertising space, screens can offer a way to reach people while they are already shopping. For a brand, the appeal is proximity to the purchase decision.
Neither benefit guarantees profit. A campaign’s value depends on the cost of advertising, the margin on additional products sold and what customers would have purchased without seeing the screen. A sales increase is not the same as an increase in profit.
Businesses can compare similar stores or time periods, use a suitable control group where possible and measure total category sales alongside the advertised item. They should also account for installation, maintenance and production costs.
Our earlier report on display advertising looked at a different question: how an ad in a simulated online store can shape expectations before a shopper examines a product.
Evidence from one retail setting
The in-store research covers campaigns in a particular grocery setting, not every type of store, customer or advertising network. Screen design, product placement and shopper behavior can differ substantially elsewhere.
The practical lesson is to test what happens at the point of sale rather than treating the number of screen impressions as the result. A useful campaign must reach shoppers and generate enough additional, profitable sales to justify its cost.
