Oops, I Bought It Again: How Marketing Messes with Your Mind

It’s no secret that advertisements sneak into nearly every corner of our lives – from bus stops and radio jingles to the very clothes we wear. This constant exposure to advertisements subconsciously influences what we buy, even if we are unaware of their impact. Supermarkets are notorious for using psychological concepts to shape your buying behaviour, from the music played to limits on the amount you can buy.

Back in 1998, Wansink and his team ran an experiment in a supermarket to see how limits on purchases might affect buying behaviour (1). Shoppers were offered discounted soup with one of three conditions: no limit, a limit of 4 cans per person, or a limit of 12. On average, those given no limit bought about 3.3 cans, and those with a limit of 4 bought around 3.5. But here’s the kicker: when the limit was bumped to 12, sales increased by 112%, with an average of 7 cans per buyer!

This crazy increase in sales is because of an effect called anchoring. It’s a mental shortcut where people rely heavily on the first piece of information they see in a decision-making context (2). So, when shoppers saw a sign saying, 'Limit 12,' they tended to buy more than they normally would because the high limit subtly suggested that buying a larger quantity was expected.

Even the music playing in a store can quietly influence what you buy—and how much! In one study at a wine shop, researchers found that background music had a surprising effect on customer choices (3). When French music played, shoppers reached for more French wine. When German tunes were on, German wine sales went up. What’s even more surprising is that when people were asked why they picked the wine they did, none of them mentioned the music—they didn’t even realise it had affected their choice of beverage!

The way products are placed on store shelves also plays a huge role in influencing consumer choices. Have you ever noticed how products at eye level seem to catch your attention more than others? That’s not by accident. Retailers carefully position products at different eye levels to maximize sales. Studies show that items placed at eye level are more likely to be chosen because they’re simply more visible and accessible (4).

Shoppers tend to gravitate toward products they can easily spot and reach, meaning that products at the middle shelf, where they align with the average shopper's line of sight, are often the ones with the highest sales. This is why you'll often see well-known or high-profit margin items placed in these prime spots.

The strategy is not limited to a single store aisle. For example, in the cereal aisle, you’ll find that the leading brands are positioned right at the middle, while the store, often cheaper brands or lesser-known options are placed higher or lower, where fewer customers will notice them.

All of these are perfect examples of how marketing can shape our choices without us even noticing. So next time you’re shopping, keep an eye and an ear out for the little tricks that might be nudging your cart in a certain direction.

Emily Conway

1. (4) Anderson, E. T., & Simester, D. I. (2013). A step-by-step guide to studying retail pricing and product placement: How eye-level shelf placement affects consumer purchasing decisions. Journal of Marketing Research, 50(3), 333-343. https://doi.org/10.1509/jmr.12.0011
2. (3) North, A. C., Hargreaves, D. J., & McKendrick, J. (1999). The influence of in-store music on wine selections. Journal of Applied Psychology, 84(2), 271–276. https://doi.org/10.1037/0021-9010.84.2.271
3. (2) Kneepkens, P. (2023). The Power of Purchase Limits - RGM Consultancy. RGM Consultancy - RGM Consultancy. https://rgmconsultancy.com/revenue-growth-management/the-power-of-purchase-limits/
4. (1) Wansink, B., Kent, R. J., & Hoch, S. J. (1998). An Anchoring and Adjustment Model of Purchase Quantity Decisions. Journal of Marketing Research, 35(1), 71. https://doi.org/10.2307/3151931