Selling is not just a matter of having a good product, a great team or a well thought-out campaign. Selling is really about understanding how people think and decide. And in that, cognitive biases play a key role.

A cognitive bias is, in simple terms, a mental shortcut. Our brain is programmed to make decisions quickly, without having to analyze all the available information. It is a matter of survival: if we had to evaluate every little decision rationally and logically, we would collapse.

These shortcuts help us decide quickly... but they also cause us to make systematic and predictable mistakes. And the interesting thing - if you have a business, sell something or are creating a project - is that you can use these biases to make it easier for your customers to make decisions. It's not about manipulation, it's about designing the experience better: making it easier to say «yes».

Big brands, leading startups and local businesses do it. Sometimes consciously. Sometimes simply because they've learned what works. But you can go one step further: understand why it works, and apply it with intention.

We're not going to talk theory here. Let's focus on what matters: how to use these biases to improve your sales, build more trust and create experiences that convert better.

Shall we go there?

Cognitive biases:

1. Bandwagon effect (or “jumping on the bandwagon”)

People, by nature, are social. We don't like to feel left out of the group. The bandwagon effect describes the tendency to adopt behaviors, ideas or decisions simply because others have already done so. It is no coincidence that products or services that are presented as popular sell more. When we see that many people have already bought something, our brain interprets it as a safe bet: if it works for many people, it must be good.

This bias is closely linked to the fear of being left out (FOMO), and is especially powerful in the age of social media, where popularity is measured in real time: “50 people are viewing this product now”, “More than 3,000 satisfied customers”, “Edition sold out in 24 hours”.

2. Certainty bias (or risk aversion)

We would rather lose less than gain more. It's as simple as that. Our brain is programmed to avoid pain, loss and uncertainty. This is known as “risk aversion”. Even though rationally something may be a great opportunity, if we don't perceive it as a sure thing, we often don't want it.

This is where the certainty bias comes into play: we need guarantees, certainties and clear signals that we are not going to make a mistake. If you don't give it to the customer, his brain triggers the “better not move” alarm. On the other hand, if you offer them a smooth path, they will buy from you with more peace of mind.

“Try it free for 14 days. No credit card required. Cancel at any time.«. This type of messages play with our mind with the idea of giving us certainty and can be decisive when we make a decision in one direction or the opposite.

3. Decoy effect

This bias reveals that we do not always decide based on absolute value, but by comparing options. And this is where the “lure” comes in: an option that is deliberately less attractive than another that we want to highlight. By introducing a third (usually intermediate) option, we push people toward the decision we are interested in.

For example, if you offer two plans (one cheap and one expensive), many will choose the cheap one. But if you introduce a third one, similar in price to the expensive one but clearly inferior in value, the expensive one starts to look like the better option. The customer thinks he has made a free choice, but you have designed the decision.

Imagine that a SaaS presents three plans:

• Basic: 9 €/month
• Professional: 15 €/month
• Business: 18 €/month

The €19 plan becomes a lure to push the customer to the €18 plan, which has considerably more advantages for only €3 more.

4. Scarcity bias

Our brain associates “scarcity” with “value”. If something is limited, it must be special. This bias has evolutionary roots: in times of scarce resources, the rare was valuable and we had to act fast. Today, although survival is no longer at stake, we still react the same way.

Phrases such as “LAST UNITS”, “only today”, o “exclusive access”The more authentic the message is (i.e. if there are really few units or if the promotion really ends), the more effective it will be. And the more authentic this message is (i.e. if there are really few units or if the promotion really ends), the more effective it will be. But be careful: if the customer perceives it as an empty or repeated tactic, the effect is diluted and you may lose credibility.

5. Authority bias

When an authority figure says something, we tend to assume he or she is right. This bias is based on our tendency to delegate decisions to experts or people with status. From childhood we learn that we have to listen to the teacher, the doctor, the boss... and this carries over to consumption.

This is why expert testimonials, institutional validations, or even influencers (when they are perceived as referents) work so well. It's not just about being right: it's about appearing to be a trusted source. And if your brand projects that leadership, the purchase decision is simplified for your customer.

Phrases such as “Recommended by dermatologists. Certified by the Spanish Society of Dermatology.”completely change the perception of the product.

6. Confirmation bias

People do not seek the truth. We seek to be right. This bias consists of filtering information to confirm what we already believe. When we find a product, a brand or a message that fits our worldview, we accept it more readily.

This implies that it's not enough to talk to everyone: you need to know your audience and connect with their values, beliefs and priorities. If you succeed, your customer will feel that you have read their mind... when in fact what you have done is to align your message with what they already expected to hear.

In politics it is used a lot, but in product sales it is used no less. “Additive free, sugar free and 100% vegetable. Ideal for those who take care of their health without giving up taste.”. This phrase alludes directly to those who have internalized healthy eating, and reinforces the image and message they project to themselves as healthy people.

7. Halo effect

Our brain tends to generalize. If we like something about a person or product, we assume that the rest will also be good. This is what happens when we think that someone good-looking is also smart, or that a well-designed website means that the service will be excellent. It's not logical, but it's very human.

This effect can work in your favor if you take care of the details: a good design, a neat packaging, a smooth experience... all this can improve the overall perception of your product or brand, even before the customer has actually tried it.

A restaurant with an elegant digital menu, professional photos and an impeccable website generates the perception that the food will be of quality... even before tasting it.

8. Anchoring effect

The first number presented to us acts as a reference, or “anchor”, and conditions our perception of what comes next. If you first see a 500 € product, a 300 € product will seem cheap. But if you first see a €100 product, that same €300 product will seem expensive.

This bias is extremely useful in pricing, discounts and offers. Presenting the original price before the discounted price (even if it is symbolic) makes the final price be perceived as more valuable. And if your strategy includes upselling or premium products, the order in which you show them can make a big difference.

Events such as Black Friday appeal, among others, to this bias. They play on the perception that the products on sale are a bargain, a great opportunity. They use discount percentages (often fictitious), emphasize the previous price so that you can compare it with the new one... A classic among classics.

Conclusions

Cognitive biases are not cheap tricks or obscure tools of manipulation. They are deeply human mechanisms that influence - whether we like it or not - how we make decisions. Understanding them not only allows you to sell more, but to sell better: facilitating choice, building trust and connecting with what really moves your customers.

The key is to apply them ethically and intelligently. In my opinion, the idea is not to deceive (although many use them for that purpose), but to design shopping experiences that are more fluid, more persuasive and more aligned with how the human brain works. And that, today, is a real competitive advantage.

So don't wait for others to do it. Start reviewing your messages, your website, your pricing and your strategy with this new look. Because when you sell the way people think, you sell much better.

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