The Top Three Cognitive Biases Uses (and You Should Too)

Disha Sharma
May 18, 2020 ·

NOTE: This blog is extracted from the research conducted by Tim Zuidgeest of Unravel Neuromarketing Research

Not all optimizers would know the 168 cognitive biases that tap right into a prospect’s subconscious and act as that final, “converting” touchpoint.

But being a neuromarketer first, optimizer Tim Zuidgeest from Unravel Neuromarketing Research knows them. He knows better than most of us how the consumer brain, the black box that marketers want to decipher, works.

So can a website optimized for conversions — using the same cognitive hacks Tim uses to generate more revenue for his clients — get him to convert? Or unlike you and me, can he simply stay “debiased” and tiptoe his way out, unswayed by the tens of very carefully placed conversion elements as he navigates them?

As it turns out, knowledge isn’t always power. Cause Tim too was taken into the loop by the cajoling on-site (yup, they’re potent).

But he decided to do something about these uber effective principles. He decided to decode them into a 6000-word synopsis that grabbed eyeballs everywhere and even earned him a high five from’s Co-founder.

We at Convert got the privilege to dig into this seminal work of Tim. And we’re glad to bring you three of the top cognitive biases that have propelled Booking to 88 billion dollars.

And here they are!

Base Rate Neglect

The base rate neglect bias kicks in when you — instead of looking at all the information before you — place more weight on some specific piece(s) of information. And as a result end up misjudging the full picture.

Marketers use the base rate neglect principle to subdue the users’ attention on their general information and shift it to some specific items that will get them to act.

Throughout his booking experience on, Tim stumbled across several instances of the base rate neglect principle in action. He repeatedly saw prompts that made him ignore general information (like the overall capacity of some accommodation) and focus on the specifics (that were primed to get him to act ). For example:

  • “15 people are currently looking at this room.” Now, 15 people might be looking at this room, but hey there are 150 exactly similar rooms in the hotel!
  • “4 other people looked for your dates in the last 10 minutes!” Great, but did they even search for THIS hotel? Or the gazillion properties hosts?
  • “Booked 5 times for your dates in the last 12 hours.” This one is slightly more “fact based”. But again, if you are looking at a hotel then what % is 5 rooms? 50%? Or just 10% of the total hotel capacity?

As you can see, these prompts are strategically placed to create a sense of urgency.

And the urgency clouds the better judgment of us simple humans, moving us to act (book), when common sense and math would show that taking our time is absolutely fine, and we can even look at other options (gasp!)…without this one disappearing forever.


Scarcity, the sixth of Dr. Robert B. Cialdini’s principles of persuasion, makes you suddenly find something to be more valuable and desirable, simply because it’s scarce (or you perceive it to be so).

This principle explains why a popular celebrity or brand’s “limited” edition sells out fast or why people rush to help themselves when the bartender makes the “last call.” The mere fact that something is available only in a scarce supply or only for a certain period consumes our minds and we want to act fast (almost on impulse) without giving much thought into the validity of the statement.

Or even if we do need that “scarce” item at all in the first place.

For marketers, scarcity has always been a go-to conversion hack, especially for ecommerce websites.

Whether it’s sales campaigns that work on an invite-only basis or holiday campaigns with large countdowns, the scarcity principle is hard to bypass.

On, Tim was repeatedly pitched rooms with prompts stressing on how soon they could book out:

  • “Deal of the day room.” A standard time-based scarcity tactic promising a great price for the room today, but only for today.
  • “‘See our last available rooms >.” A loud and clear statement hinting at the idea of the hotel getting booked out soon.
  • “Great value today!” Again, no promise here of getting a great value tomorrow but comfortable ambiguity around what “great value” looks like.

Not just these, Tim was also shown an accommodation that was booked out. Why?

As Tim explains, to stress even more on how scarce the availability could be and how one needed to book, like really fast, to get a good room.


Also, while it might look strange to see an unavailable thing (a hotel room, in this case) being placed so prominently before a lead on a website, it’s not so uncommon. This deliberate tactic effectively creates a sense of immediacy, and works even in the offline world (think empty shelves that get you to stock).

Commitment and Consistency

Commitment and Consistency
Source: TravelGroove

The principle of consistency works because of the interpersonal pressure you have to feel (and be) consistent with whatever you’ve committed to.

Meaning once you decide to do something (or say a yes to a small ask), you’d be more likely to stick to your decision and follow it through (or say yes to the subsequent, bigger asks).

Savvy marketers use the principle of consistency for everything, right from generating leads (making low stakes offers like a free ebook download followed by the high stake ones) to encouraging people to complete their signup process (with UI elements and micro copy that tug at their inherent behavioral impulse for staying consistent).

Tim encountered multiple instances of the consistency principle on the website.

Once he began the booking process, he was reminded in myriad subtle ways of his initial commitment and his decision to initiate the booking process, thereby pushing him to be consistent and go to the finish line:

  • “Risk Free: You can cancel later, so lock in this great price today!” Reading minds? Booking understands that the moment before commitment is the most antsy. So it goes for the proverbial jugular, addressing the resistance point of risk right away. This removes any anxiety around staying consistent.
  • “You selected:” Also on the reservation page, you have a simple but clever hack showing you the accommodation you chose. You just took action and “selected” something. Now don’t back up on your virtual word by abandoning the process.
  • “Almost done.” This alone makes you feel good that you stayed consistent with your decision and pursued it, and that you’re almost at the finish line.

Multi-step forms, progress bars, UI design and copy elements are some of the most effective tools that marketers use for implementing this principle.

The key to getting great results, however, lies in making the initial commitment easy and small. Because from that point onwards you’ll have the prospect’s desire for consistency working for you.

Ethics and All

Listen, you must have known about these biases all along. What Booking does is it takes psychological principles that are often difficult to understand and shows exactly HOW they can work in the real world for very real profits.

Before we wrap this up though…there is a word of caution.

Neuromarketing has always been powerful.

And now it’s accessible too.

For example, some time back, $50,000 would let you tap into how your stimuli (marketing messaging or images) affect the electrical signals of about 30 of your prospects’ brains. And then experiment with your greater audience by extrapolating your findings. 

Now, however, such research is much “cheaper.”  For instance, a qualitative study with 10 participants would ‘only’ set you back € 7700.

But given that the brain only uses 2% of its energy for conscious activity, all the unconscious processing — that neuromarketing principles appeal to — can affect consumers in more ways and to higher degrees than they’d be comfortable with.

Jeff Chester, executive director of the Center for Digital Democracy, raises concerns about the same. He says: “It’s having an effect on individuals that individuals are not informed about,” and should be regulated. He also explains that while adults have defense mechanisms that can help them differentiate between what’s true and not, advertising that’s “purposely designed to bypass those rational defenses” calls for better legal defenses.

As the field evolves and regulations and legislations catch up with its innovations, we can still use these guaranteed-to-work principles. The only caveat: We need to use them responsibly. And ethically. Tim and his firm, for instance, use the “mom test” before taking on a client or project. They only help a business unleash the power of neuromarketing if they’d be comfortable with their moms engaging with it. So tell us: Have you ever experimented with any of these brain hacks? And where would you draw the line (because we can all agree these principles go deep)?

Tim Zuidgeest
Tim Zuidgeest
Originally published May 18, 2020 - Updated November 10, 2022
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Disha Sharma
Disha Sharma Content crafter at Convert. Passionate about CRO and marketing.
Carmen Apostu
Carmen Apostu In her role as Head of Content at Convert, Carmen is dedicated to delivering top-notch content that people can’t help but read through. Connect with Carmen on LinkedIn for any inquiries or requests.

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