Your Brain on CRO: How 7 CRO Best Practices Affect the Human Brain



If you work in digital marketing, you’re probably very familiar with conversion rate optimization best practices.

Though we know it’s important to test everything, these best practices remain a good foundation for building high-converting landing pages, popups, and more.

In this article, I’m going to take a look at 7 of the best-known CRO best practices and how they affect the human brain, to find out exactly why they work.

1. Reducing Form Fields

Conversion rate optimizers harp on this all the time: ask only as much as you need to. There are countless case studies centered around the notion that less is more when it comes to forms.

Though this isn’t always true, it’s a good rule of thumb to remove any form fields that aren’t necessary – you probably don’t need a visitor’s credit card number to sign them up for your blog newsletter.

Adding form fields adds significant friction. What is friction? The Complete Guide to Understanding Consumer Psychology from Quick Sprout defines friction as “any variable, website quality, or user behavior trend that is slowing down the progression of your company’s sales cycle”.

In this case, adding form fields increases friction because a visitor is aware of the amount of information they need to provide. Though what is considered “too many” can vary from person to person based on their previous experiences, you still want to minimize the number of unnecessary fields you use.

Adding form fields not only increases the work each visitor needs to do, but also can introduce a feeling of unease, especially when you ask for information like a visitor’s phone number or address.

This has potential to harm the trust you work so hard to build with each of your visitors through your marketing materials.

How you can apply this best practice

Sometimes, you need specific information from your visitors – and that’s fine. If you’re shipping them a free instructional handbook, then you probably do need their address – if you’re sending them a PDF, you probably don’t.

Don’t fall into the trap of copying other forms you’ve seen. Think about your the goals and objectives you have for the campaign attached to each form you create.

What will you do with the information you receive from visitors who convert on your forms? Think about the information you need to take the next steps in your sales funnel.

And remember, less fields isn’t always better. Yes, deleting extraneous form fields is, in most cases, a good practice – but don’t be afraid to add fields if you think it will increase customer engagement.

2. Employing Design Hierarchy

As a designer myself, designing to maximize conversion rates is always of particular interest to me. One of the most intuitive design concepts within the CRO space is what’s called hierarchy: “when an element appears more important in comparison to other elements in a design”.

Essentially, when designing something like a landing page, the manner in which you arrange the elements of your page can serve to emphasize (or de-emphasize) their importance. Make sense?

Hierarchy can be further broken down into three primary elements: size, shape, and placement. These three variables can help you highlight certain objects on your page (or what have you), allowing you to draw viewers’ attention to things you want them to see.

From a psychological point of view, design hierarchy is a rather simple concept. We’re so exposed to it in everything we see – advertising, photography, even music – that it’s become ingrained in our minds on a subconscious level.

Being conscious of these design elements and how they can affect the human brain can help us maximize the effect we can have on our conversion rates. Let’s use this flyer from Best Buy as an example (because we’re all sick of landing pages by now):

Size: Best Buy uses two size “tiers” to highlight special deals from this page. In this case, the larger items on the page are more expensive – Best Buy uses size to draw readers’ attention to big-ticket items.

These items also have greater discounts; by making them larger, Best Buy suggests to viewers that they should act quickly on these deals.

Shape: The use of shape to create hierarchy isn’t so apparent on this page, but there are a few examples of it. Most apparent is the green “best gift” symbol on one of the top left Nespresso coffee makers.

Besides being appropriately shaped like a wrapped Christmas gift, it is the only element on this page shaped this way – this provides an element of contrast to help pull a viewer’s focus to this item.

Placement: This page uses placement for the same purpose as size, putting big-ticket products with big discounts front and center to pull viewers’ attention.

The left trimmer in the bottom-right quadrant commands more attention because it’s placed adjacent to two other products; its unique placement helps to pull attention.

How you can apply this best practice

I think by now it’s pretty clear how you can use hierarchy to pull attention and importance to certain elements within your designs. Their main use is in creating contrast between elements to pull and direct viewer focus.

As far as best practices for this best practice go: don’t overdo it. Not every element needs to be a different size, and you don’t need to have seven different shapes – at that point, you’ll need a legend to explain each of them.

The more you use these hierarchical design tricks, the less effective they are. Remember at the end of the day that hierarchy is meant to pull focus – so only use it for bits and pieces that need to demand a viewer’s attention.

3. Implementing a Countdown

I can’t count the number of times I’ve added an item to my cart on an e-commerce page, only to hesitate, say “maybe later,” and close the page, making a mental note to come back.

Problem is, I usually don’t… and I’m willing to bet there’s a lot of people like me.

Let’s think of some reasons that might explain why this happens…

  • I forget
  • I find alternatives
  • I find the same item for a lesser price elsewhere
  • I decide I don’t want the item
  • I balk at the shipping cost
  • I wait too long, and a discounted item is no longer on sale

Any of these feel familiar to you?

It’s a common occurrence, and it’s not consumers’ faults. The burden is on the brands selling their products to push consumers to act.

One of the most common tactics they employ to achieve this goal is implementing a countdown. Countdowns come in many shapes and forms – the most common is a countdown timer

Here’s an example:

Okay, great. So what does this do?

This kicks the brain into gear by giving them a concrete reason to act immediately. In other words, it creates urgency. At the end of the day, most companies probably don’t care too much about whether a customer buys sooner or later.

But more often than not, this decision is now or never – and brands need to minimize the number of customers who fall to “never”.

Creating urgency helps to push customers into acting (the fact that they do it immediately is a bonus) in the first place. Rather than giving me time to fall into indifference, or forget, or find alternatives, invoking a sense of urgency in potential customers works to keep customers around long enough to make a decision.

Every all-nighter I pulled during my university years was a product of the panic generated by my incessant procrastination. I was pushed to act because of a sense of urgency – I need to do this now, or I’ll miss out.

Implementing a countdown of some sort is one of the simplest and most effective ways to get potential customers to act. My colleague James put it best: “Creating urgency within your website and landing pages isn’t about pressuring people to make the purchase. Rather, it’s about giving people a reason to stop procrastinating.

How you can apply this best practice

Seems simple enough, right?

At the bare minimum, if you’re holding some sort of sale or hosting a contest, use a countdown timer (or plaintext countdown) on your homepage that links to your sale items or entry page.

This directly links your instrument of urgency with the action you want your customers to take.

If you’d like to go one step further, implement a popup of some sort (entry or exit popups work best here) offering an additional limited time discount in exchange for an email address.

This not only doubles down on your customers’ sense of urgency, but also allows you to send further email correspondence to increase the chances they will convert.

If they’ve added items to their cart without buying, send emails with subject lines including copy like “Only 4 Days Left to Get Your [Item]”. This helps to pull customers back into your funnel and renew the sense of urgency they felt when they first looked at your site.

Finally, don’t overdo it – if they still haven’t converted after two or three emails, they’ve probably made up their mind.

4. Social Proof

It should be no surprise that social proof runs so rampant in a marketing era so heavily defined by social media. Followers, likes, comments – the list goes on, and on, and on.

What is social proof, exactly? It’s a type of conformity in which people use the actions of others to determine the correct behaviour in a certain situation. In marketing, the number of followers a company has on Twitter may influence your decision to follow that company, interact with them, or purchase from them.

On Facebook, you’ve probably seen posts like this:

This is a sponsored post by Frank + Oak – and right at the top, Facebook is telling me that 15 of my friends like the brand on Facebook. I’m assuming this decision came after running tests on millions and millions of users and finding this improved conversion rates.

It’s a perfect example of social proof. Your friends like this, and so should you.

Here’s another example of social proof, straight from our friends at Buffer:

Those 42,023 people are there to convince you to subscribe to Buffer’s newsletter. This example also appeals to another psychological phenomena that’s probably familiar to you: the fear of missing out, or FoMO.

If you don’t know what this is, it’s the idea that others might be having fun – without you. According to Wikipedia, it’s characterized by “a desire to stay continually connected with what others are doing” and is especially prevalent with the widespread use of social media.

Here’s an example: you stay in while your friends go out to a bar. Later that night, you see their Snapchats and start to feel regret – that’s FoMO.

Buffer appeals to potential subscribers with the idea that 42,023 other marketers are receiving their content first, and thus will be “in-the-know” immediately.

The certain type of FoMO this induces is probably more to do with the competitive nature of marketers – everybody wants to be on the leading edge when it comes to the latest trends and news.

How you can apply this best practice

You can use this in a ton of different ways. Mention the number of customers you’ve had in your ads, or brag about your social media stats when convincing people to engage with you on social.

Like Buffer, talk about how many blog subscribers you have to get others to subscribe to your newsletter, or find a way to link to Facebook’s API and show people that their friends like you.

Of course, you want to make sure you have good numbers before you do this. It’s not so impressive to show off your 20 Facebook fans or your 4 happy blog subscribers. It’s a much easier strategy to employ when you’re looking to go from big to bigger, once the numbers are already on your side.

5. Match Ad and Landing Page Copy

One of the biggest mistakes I see when looking at landing pages is a mismatch between the copy used in ads (on Google or Facebook) and the copy that’s on the landing page itself.

Here’s a good example of matching ad and landing page copy:

As you can see, Apple’s ad saying “This is 7” matches the copy on the top of the iPhone 7 landing page. This creates a seamless experience for the viewer from the time they stumble upon the ad to the time they reach the page. Because they know what to expect, they’re eased into the landing page and are more likely to convert.

Why is this a best practice, and why is it so important?

Matching ad text to landing page copy allows marketers to avoid inducing an admittedly tame bout of cognitive dissonance in viewers. Cognitive dissonance is the mental stress or discomfort that a person experiences when they are confronted by new information that conflicts with their existing beliefs, ideas or values.

Though you’re probably not going to have contradictory information between your ads and landing pages, you’re still at risk of evoking cognitive dissonance in would-be customers by having mismatched text.

Ad copy doesn’t only serve the purpose of getting ad viewers to click – it’s also there to prime them for what’s ahead. Think about it this way: someone who clicked your ad took that action based on what they read on it.

Wherever this person ends up, they want to see what they clicked on to begin with. This prevents a mental “disconnect” once they’ve reached the landing page.

Everything people see before and even after they’ve converted on your landing page contributes to a singular experience with your brand – keeping this experience consistent is the key to maximizing conversion rates for clicks coming from your ads.

How you can apply this best practice

Just do it. Really!

Make sure the copy you include in your ad appears somewhere above the fold on your landing page. It doesn’t need to be the headline (as in the Apple example), but that’s not a bad place to start.

This extends beyond copy, and beyond ads and landing pages. Your checkout page should look visually similar to your landing pages, and the emails you send out to your leads should carry the same tone as your landing page copy.

Your goal here is to minimize the risk that you invoke feelings of cognitive dissonance in viewers by maximizing consistency amongst your marketing materials.

Even if viewers pass through multiple channels – AdWords, social, your own webpage, a standalone landing page – they should feel as if these channels are all linked in some way. Though copy is a place to start, consider looking over other aspects like your visual design as well.

6. Emotional copy

In economics, we often assume people make decisions rationally, based on the concept of maximizing utility. If this were truly the case, buyers would always choose the product with the most features at the lowest possible price, making marketing a redundant task.

Thankfully, this isn’t the case. As we know, emotions play a large part in consumer behaviour. Things like brand loyalty, nostalgia, and emotional reactions to marketing materials can heavily affect the way buyers make decisions.

First, let me give you some background information. The philosopher Aristotle defined three “appeals” – ethos, logos, and pathos – that formed the “rhetorical triangle”.

Aristotle identified ethos, logos, and pathos as the three main ways in which someone could persuade others to take a particular point of view.

Ethos is an appeal to ethics or credibility. For example, if I was selling you a shirt, I might say “my friend, a designer of over 20 years from Paris, says this is one of the highest-quality shirts she’s ever seen.”

Logos is an appeal to logic. For example, “after extensive testing, we found our shirt lasted three times as long and faded ten times slower than shirts from other brands.”

Finally, pathos is an appeal to emotion. “This shirt will make you the most fashionable man in the office.”

As I’m sure you’re aware, we see many examples of these three things in marketing. After a while, however, it’s easy to become numb to lists of features or testimonials from experts.

Emotional triggers in your copy can jolt readers out of indifference and into making the decisions you’d like them to take.

Emotional copy succeeds because it helps your copy stand out from others’ – it’s a way to make your marketing unique in an ever-expanding sea of data.

It helps make potential customers care about your product beyond its features – it creates a deeper connection between them and your product that’s much more likely to result in a conversion or sale.

How you can apply this best practice

Okay, I know I was pretty vague about this above. This is because emotional copywriting covers such a wide range of feelings.

Though you might be inclined to lean towards positive emotions like happiness and excitement, there’s an entire spectrum of emotions you can take advantage of to increase your conversion rate.

Let’s highlight a few unique emotions and how you might use them in your copywriting…


Often, appealing to people’s sense of fear or doubt is an effective way to convince them to convert. These emotions are used often in health or safety initiatives – for example, pregnancy scares to market birth control.

To capitalize on fear in marketing, think of negative situations that might arise without your product.


People are more likely to buy from brands they trust. Makes sense, right? That’s why brand equity and loyalty are such important metrics in marketing – they’re a measure of a brand’s trustworthiness, which can have a direct impact on sales.

Though it can be hard for small brands to build trust with consumers, you can add things like “no-questions-asked return policy” to your copy.


Though people will likely already want your product if they’re purchasing it, highlighting that desire and putting it front and center will aid in strengthening your emotional appeal.

Think about the benefits your customers seek from your product – what will it help them achieve in their lives? You see this type of marketing often in fitness: “get the body you’ve always wanted.”


Seems strange, right? Why would you want to associate such a negative emotion with your product or brand? But think about it – people gravitate towards movies that make them cry.

Buffer cited a study by Paul Zak that showed sadness produces oxytocin in the brain – a hormone that promotes connection and empathy. Sad stories in advertising or marketing can help build trust in a brand to increase sales.


“Your donation helps children in need.” People like to believe they’re naturally altruistic – so when they’re forced into a situation where they need to prove this, they often cave under the pressure.

I know I often say “sure, why not” when I’m asked to donate a couple dollars at Costco. If you’re trying to do marketing for a charitable or non-profit organization, think about appealing to guilt in your marketing (but be ethical about it!).

7. Loss Aversion

Ever seen an exit popup like this?

I don’t want to convert on this popup overlay… but, wait! Stop! I do want more traffic!

This is a trend in lead generation that is everywhere – and much like popups themselves, people don’t like them. In fact, someone hated them so much they made a Tumblr blog with examples of what they call “confirm shaming”. An article on Vice’s Motherboard blog calls confirm shaming “inherently predatory”.

But based on their popularity, it’s clear that this kind of “no thanks” copy has become the norm when it comes to exit-intent popups.

So why does it work?

This plays on several theories and tendencies present in psychology, economics, and decision theory.

First, the concept of loss aversion: Wikipedia explains loss aversion as “people’s tendency to prefer avoiding losses to acquiring equivalent gains”.

To put it simply, people hate losing more than they like winning – some studies show that losses are twice as “powerful” as gains.

The second of these concepts is prospect theory: the theory that describes the way people choose between alternatives based on the potential value of losses and gains. Again, this theory highlights the idea that people place a higher value on losses than gains.

When you take these two theories into account, this “confirm shaming” actually makes sense when you put it into practice. The “No thanks, I don’t want more traffic” response from Neil Patel’s blog is more effective than a “I want more traffic!” response would be.

The viewer places more importance on the idea that they might be losing out on traffic by closing the popup, than the idea that they could gain more potential traffic by converting on it.

Because of this, a viewer is likely to convert on the popup, even if only because they’re worried about losing out on traffic as opposed to increasing it.

How you can apply this best practice

If you haven’t already, add exit popups to your pages – there’s a reason they’re so popular nowadays! Combine an exit popup with some sort of incentive – a discount, free trial, or content upgrade – to convince people to convert.

Once you’ve implemented this popup on your pages, tweak the copy for your “No thanks” response to include an element that appeals to a viewer’s sense of loss aversion. Keep it related, and not too ridiculous (“No thanks, I don’t want one million dollars” is… not so great).

Make it humorous, even. Just make sure your copy implies your viewer is missing out on something they deserve, because that’s how you’ll invoke that “losing” feeling you need to take advantage of loss aversion.


There you have it – a breakdown of 7 of the most common conversion rate optimization best practices and their effects on human psychology. Pretty neat stuff.

Any other CRO best practices you find interesting? How have the practices above worked – or not worked – for you? Let me know in the comments below!


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