Table of Contents
A cognitive bias in marketing is a mental shortcut that can make buyers see things in a skewed way or make purchase decisions that aren’t fully rational. Brands use cognitive biases by presenting what’s popular through social proof or making products seem limited to promote purchases.
Introduction: how our mind buys
We like to believe every purchase we make is a rational choice, based on pros and cons. The truth is, a lot of what drives us happens beneath awareness. Harvard professor Gerald Zaltman argues that 95 % of our purchase decision making takes place in the subconscious mind.
That means when a customer sees your ad, packaging or headline, their brain is already filtering whether it “feels right” before logic even kicks in. In marketing, the brands that influence that inner filter gain more power than the ones that only shout features and specs.
When we understand these biases, marketing efforts can focus on presenting products in ways that naturally match how people think and decide. By exploring anchoring, scarcity, and social proof, you’ll see how your messaging, pricing, and social signals all feed into the same underlying brain patterns. The rest of this blog post shows how each bias plays out in buying behaviour and how you can apply that insight in your campaigns.
Anchoring: the first price always wins
Anchoring is a cognitive bias where the first number people see becomes a reference point for all decisions that follow. In pricing, it means the first price a customer sees influences how they judge the value of a product or service. Here’s how it works in practice:
- A retailer lists the product as “Was €150, Now €99”. The €150 becomes the anchor, making €99 feel like a strong deal even if €99 might still be high for that item.
- A pricing page shows three tiers: Premium €90, Standard €60, Basic €30. Because the Premium is listed first, the Standard appears well-priced or more reasonable.
- An experiment at Ohio State University showed when a small coffee was priced at $0.95 and a large at $1.20 only 29% picked the large size, however when the small was $1.00 and the large $1.25 (same difference) the large size jumped to 56%. The higher anchor made the “upgrade” seem much more acceptable.
Research shows that when consumers judge product prices in “real‐life” scenarios, anchor values consistently change their estimates. For example, high anchors lead to higher price estimates and lower anchors to lower ones.
Scarcity: the power of “Almost Gone”
Say you land on a product page and see a message like “Only 2 left!” or a clock counting down from 00:59:59. Instantly you feel you might miss something. That’s the essence of scarcity in marketing.
People interpret limited availability as a sign of something valuable. When something looks rare, our brain treats it as way more desirable. A meta-analysis covering 131 studies and 416 effect sizes found that scarcity increases buying intentions, particularly when they involve limited supply, time limits or both. Another study found that scarcity creates fear of missing out (FOMO), which drives impulse buying.
An example of scarcity tactics working to full extent can be found with Zara, one of the top fashion retailers. Zara makes people want to buy clothes right away. They only make a small number of each new, trendy item. Because the items sell out fast, customers feel they have to buy them immediately or miss out forever.
How to use scarcity within your marketing:
- Clearly state the limit: specify “only X items left” or “offer ends in Y hours” so the scarcity of an item feels real.
- Tie scarcity to a genuine reason: seasonal product or exclusive access.
- Use visual cues: timers, progress bars, low-stock banners, and couple them with urgency colors like red and yellow. They turn the idea of scarcity into visual urgency.
- If your brand is built on quality or being one-of-a-kind, scarcity proves it. When something is hard to get, it feels more special.
Social proof: why we follow the crowd
When shoppers land on a product page, they often ask themselves the question: “Has anyone else done this?” Social proof answers that. It shows that other people have bought the product, used it, found value in it; and that reassurance pushes our brain from doubt to action.
Recent statistics show how strong this effect has become. One dataset shows that 90% of buyers say social proof influenced their research stage when comparing products. Another report found that websites featuring user-generated content (reviews, photos, testimonials) saw conversion rates rise by nearly 30%.
Let’s see how some brands make this work.
Glossier built its beauty empire on community sharing; customers posting selfies, tagging the brand, writing reviews and such. That created proof of use, that showed potential new customers that the brand is worth their time and money.
Airbnb does something similar: every listing includes ratings, guest reviews, and verified photos, which help build trust before someone books.
To use social proof well, focus on clarity and authenticity. Show star ratings and testimonials where people can see them right away. Use real names, faces, and numbers like “Trusted by 5,000 customers” so your proof feels real. And let customers speak for you through their stories.
Social proof works best when paired with the other two biases. Anchoring makes the price look right, scarcity creates urgency, and social proof adds reassurance that others have already made the same choice. Together, they make a product feel like an obvious decision.
Key takeaways
Understanding how anchoring, scarcity and social proof operate gives you a marketing framework that is in line with how humans make decisions in all walks of life. Here are two practical insights to carry forward:
1. Biases reflect decision-context, and aren’t manipulation.
These psychological shortcuts exist because our brains have to simplify complex choices. When you use anchoring, scarcity or social proof thoughtfully, you’re shaping the decision-context instead of forcing an outcome.
2. Integration matters more than tactics.
Using one bias alone can boost performance. However, the best formula is to layer them like this:
- Set the value with a high anchor,
- add urgency with scarcity and,
- offer confirmation with social proof;
As you review your pricing, messages and social signals, ask yourself: Which bias am I triggering and does the customer feel trusted and clear in their decision? When those pieces align, your marketing stops being guesswork and becomes predictable influence.
FAQ
1. What are marketing biases?
Marketing biases are psychological shortcuts that influence how people perceive products and make buying decisions.
2. What is anchoring?
Anchoring is when people rely heavily on the first piece of information they see, like an initial price, when making decisions.
3. How does scarcity work in marketing?
Scarcity creates urgency by suggesting a product is limited, encouraging quicker decisions or purchases.
4. What is social proof?
Social proof is when people look to others’ behavior like reviews, ratings, or testimonials, to guide their own choices.
5. Why should marketers care about these biases?
Understanding these biases helps marketers design campaigns that influence decisions more effectively and predictably.
6. Are these biases ethical to use in marketing?
Yes, when used transparently and responsibly, they help communicate value rather than manipulate consumers.
