Research Insight | Horizontal Product Displays Make the "Decoy Effect" More Powerful
Marketers must often decide how to present products on shelves, menus, and digital interfaces, where subtle aspects of the visual layout can meaningfully shape consumer choices. A Journal of Marketing Research article investigates one such factor—display orientation—and demonstrates that arranging products horizontally rather than vertically significantly strengthens the “attraction effect” (or “decoy effect”), a well-established phenomenon in which adding an inferior “decoy” option increases preference for a target option. Across eleven studies, the authors find that horizontal displays consistently produce a stronger attraction effect, whereas vertical displays often weaken or eliminate it.
When a vertical display is unavoidable (e.g., on mobile), guiding consumers to make pairwise comparisons or priming them to think vertically can strengthen the decoy effect. For example, consider an online electronics retailer offering three laptops: a high-performance model (the target), a mid-tier competitor, and a decoy that is slightly worse than the target but no better than the competitor. When displayed horizontally on a desktop site, customers can quickly compare specifications across the row and often shift toward the target. But on a vertically stacked mobile page, the same customers may struggle to notice the target’s superiority, reducing the decoy’s influence. Adding numerical ratings (e.g., quality ratings) or prompts to compare features between laptops can restore the effect even in a vertical format.
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What You Need to Know
- To strengthen the decoy/attraction effect and increase choice of a focal option, use horizontal (side-by-side) product displays.
- In vertical or mobile layouts, add cues or comparison aids to help consumers recognize which option is superior.
- Consider using numerical attribute displays (e.g., quality ratings) when vertical presentation is unavoidable, as they make comparisons easier.
Abstract
Marketers can display their products horizontally or vertically in both online and offline settings. This display orientation has been shown to influence consumers’ judgments about individual products. The present research extends the literature by investigating the moderating impact of display orientation on the attraction effect, one of the most well-established context effects in choice. A total of 11 studies, including 7 preregistered experiments, document a novel finding that the attraction effect is stronger when choice alternatives are displayed horizontally rather than vertically. This moderating influence is replicated in both consequential choices and hypothetical scenarios and shown to generalize over diverse product categories. The authors explain this influence by proposing that a horizontal (vs. vertical) display increases the ease of comparing choice alternatives, leading consumers to notice the asymmetric dominance relationship among them more easily. Consistent with this mechanism, the authors find that the moderating influence of display orientation attenuates when individuals are guided to recognize the asymmetric dominance relationship or when their ability to compare vertically displayed products is momentarily enhanced. The present research thus demonstrates a significant effect of spatial orientation on the comparison and evaluation of alternatives. Theoretical and managerial implications of findings are discussed.
Jungkeun Kim, Jongwon Park, and Harmen Oppewal, “The Impact of a Horizontal Versus Vertical Product Display on the Attraction Effect,” Journal of Marketing Research, 63 (4), 626–43.