How Subconscious Cues Impact Buying Decisions
Most people, if you asked them, would say they buy things for pretty rational reasons. This one was cheaper. That one had better reviews. This brand fits my needs. And a lot of the time that’s true, or at least it’s the story we tell ourselves afterward. But a huge amount of what actually pushes a purchase decision one way or another happens below the level we’re consciously aware of. Music, color, scent, the order things are arranged in, even the weight of a product in your hand: these all shape buying decisions without the shopper ever noticing they’re being influenced.
This matters enormously for marketers. If we only designed for the rational, conscious part of the customer’s brain, we’d be ignoring most of what actually decides the sale.
What Do We Mean by “Subconscious”?
We’re not talking about anything mystical here. We just mean cues that a shopper’s brain registers and responds to without the shopper deliberately noticing or reasoning about them. Nobody walks into a store thinking, “the lighting in here is warm and slightly dim, so I feel relaxed and I’m going to browse for longer.” But the lighting still does that.
Researchers sometimes call this priming, where exposure to one thing (a color, a sound, a word) quietly shifts how we perceive or respond to something else that comes right after it, even though we can’t point to why.
Music and Tempo
One of the classic studies here comes from Ronald Milliman, who published research in 1982 on background music in supermarkets. He found that when stores played slower tempo music, shoppers walked more slowly through the aisles and spent more time in the store, and store sales were measurably higher on those days compared to days with faster tempo music. Shoppers weren’t aware that the music was affecting their pace. They just found themselves lingering a bit longer, and lingering longer tends to mean buying a bit more.
An even more striking example comes from a 1997 study by North, Hargreaves, and McKendrick, published in the journal Nature. They played either French accordion music or German brass band music in a supermarket wine aisle over a period of days and tracked which wines people bought. On days with French music, French wine outsold German wine by a wide margin. On days with German music, that flipped almost entirely toward German wine. When customers were later asked whether the music had influenced their choice, almost none of them thought it had. They believed they’d simply chosen the wine they preferred that day.
Think about how strange that actually is. A completely unrelated piece of music playing in the background shifted which country’s wine people picked off the shelf, and the shoppers had no idea it was happening. That’s the kind of influence we’re talking about when we talk about subconscious cues.
Scent
Smell works on us the same way, and arguably even more directly, because the part of the brain that processes smell sits close to the parts that handle memory and emotion. Cinnabon has long been known for locating its stores so the smell of baking cinnamon rolls drifts out into the mall, well before a shopper can see the store itself. That’s not an accident of ventilation. It’s a deliberate use of scent to draw people in before they’ve made any conscious decision to buy anything.
Retailers use this in subtler ways too, pumping specific scents through air conditioning systems (a practice sometimes called scent marketing) to make a store feel cleaner, more luxurious, or more relaxing, all without a customer registering that a smell is even present.
Color and Packaging
Color is another cue that works quietly. Warm colors like red and orange tend to grab attention and can create a sense of urgency, which is part of why so many clearance and sale signs use red. Cooler colors like blue and green tend to read as calm, trustworthy, or clean, which is why so many banks, tech companies, and cleaning products lean on those colors. None of this is guaranteed to work the same way for every product or every culture (color associations shift a fair bit across countries), but within a given market, color choices are rarely accidental.
Packaging weight and texture matter too. Studies in sensory marketing have found that a heavier product, or a package with a smoother, higher quality feel, gets rated by consumers as higher quality, even when the product inside is identical. Nobody consciously reasons “this feels heavier, so it must be worth more,” but the judgment forms anyway.
Anchoring and the Order of Choices
Subconscious influence isn’t only about the senses. It also shows up in how choices are presented. Anchoring is a good example: if you see a $12,000 watch sitting right next to a $600 watch, the $600 watch suddenly feels reasonable, even cheap, in a way it wouldn’t if it were the only option on the table. The $12,000 watch might rarely sell, but it isn’t there by accident. It’s shifting the reference point the customer uses to judge everything else.
A related trick is the decoy effect, where a company adds a third option specifically to make one of the other two look like the obviously better deal. Think about a popcorn stand with a small size at $3, a large at $7, and a medium at $6.50. Almost nobody buys the medium. It exists to make the large look like much better value, and it works even though most customers never consciously register that the medium is a decoy.
What Does This Mean for Marketers Making Decisions?
Once we accept that a lot of purchase behavior is shaped below conscious awareness, we have to ask what we’re actually responsible for as marketers, and where the ethical line sits.
There’s a real difference between using a pleasant scent or well-chosen background music to make a shopping experience more enjoyable, and deliberately engineering a store layout or pricing structure to trick people into decisions they’d regret if they thought about it consciously. Most of what we’ve covered here (music tempo, scent, color, anchoring) sits closer to the first category. It shapes mood and attention rather than deceiving anyone about facts. But we do need to be thoughtful about where that line gets crossed, particularly with anything aimed at children or vulnerable customers, where regulators in many countries pay close attention to manipulative design.
There’s also a practical, financial side to this. None of these tactics are free. Piping a specific scent through a retail chain, or paying for a licensed music service tuned to the right tempo, costs money. Before rolling something like this out across a chain of stores, we’d want to test it in a handful of locations first and check whether the sales lift is big enough to justify the ongoing cost, rather than assuming a technique that worked in an academic study will automatically pay for itself at scale.
We also need to think about consistency across channels. If our physical stores use warm lighting and slow music to encourage lingering, but our website is cluttered and rushed feeling, we’re sending mixed subconscious signals about the brand. As highlighted above with the wine study, these cues work quietly and cumulatively, so it’s worth thinking about them as part of the whole brand experience rather than a one-off trick bolted onto a single store.
Key Points to Take Away
- A large share of purchase behavior is shaped by cues, music, scent, color, packaging weight, that customers don’t consciously notice.
- Research such as Milliman’s supermarket music study and the North, Hargreaves, and McKendrick wine study shows these effects can be large, even when shoppers deny being influenced.
- Anchoring and the decoy effect show that subconscious influence isn’t only sensory. How choices are arranged and priced matters too.
- These tactics have real costs, so test them at a small scale before rolling them out and measure the sales lift against the expense.
- There’s an ethical line between shaping mood and atmosphere versus manipulating vulnerable customers, and marketers need to stay on the right side of it.
