5 Psychology Principles Every Marketer Should Know

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What’s a marketer’s real job? It’s to sell stuff, sure. But there are many elements to selling. It’s crafting a message, raising awareness, getting people to act.

All of that involves influencing people. Persuading them. And, to do that, we have to know people, particularly their thought processes and behaviors.

We marketers are, in a sense, professional persuaders.

If that makes you itch a little, it’s okay. It makes me itch, too. But there’s no way around it – I try to persuade and influence people all the time. Usually, I strive to get them to try certain marketing tactics, which I believe will help their business.

I try to persuade people in my personal life, too. I try to persuade my husband to do chores. I try to convince my dog to stop trying to play with the cat.

I bet you do a lot of persuading, too. At home and at work. If you’re a marketer, it’s your job to influence people to try your company’s products or services. Hopefully, you do this in part because you believe those services will help them. (And if you don’t believe they’ll help them, I encourage you to switch jobs.)

So if we’re fundamentally professional persuaders, we should know as much as we can about persuasion, right? We should understand our audiences – what motivates them, what drives them, what they like and dislike – so we can better sway them into action.

One blog post isn’t enough to cover every aspect of this complex subject, of course. But it’s enough for a refresher. I suspect that most of us who go into marketing are naturally good at the principles of persuasion. We’re interested in what makes people tick.

In other words, I bet you know most of this stuff already, whether you’re aware of it or not.

But here’s a refresher, framed specifically for you as a marketer. Hopefully it reminds you of a tactic or two to apply to your next campaign.

1. Social proof

I can’t even mention influence or social proof without acknowledging Robert Cialdini. He literally wrote the book on the subject. His best-seller, Influence: The Psychology of Persuasion, is the must-read book on persuasion for modern marketers.

While the book covers six principles of influence, I’ve cherry picked them here. The best known of all of those principles is social proof.

Social proof leverages our tendency to look to others for confirmation that we’re doing the right thing. One of the best examples of this is social share counts.

These numbers work because when we land on a page, we see those high counts and think, “Wow – this is really popular. Other people think this is important. I should read and share this, too.”

Those share counts let us set up a nice loop: Highly shared content gets more shares, simply because it’s highly shared content. But it can work in reverse. If your share counts are low, some experts recommend you use just the sharing buttons, sans counts, so people won’t see that your pages aren’t getting shared … thus giving your visitors a cue that they shouldn’t share your pages either.

While social share counts are a familiar example, social proof goes way beyond social media. It’s happening any time people refer to the behavior of others to shape their own behavior. So, for instance, the busiest booths at trade shows often stay busy, simply because their busyness attracts more people. Same goes with popular speakers or popular restaurants.

Social proof can go way beyond that, too. In a sense, influencer marketing uses social proof. So do testimonials, reviews, case studies, certifications, awards, and that list of “most popular posts” on many blogs. It’s everywhere, once you know how to look for it.

2. Reciprocity.

This is another popular Cialdini principle: When we give people something, they feel like they owe us.

Even a small gift – like a free report on an opt-in page – makes people more likely to listen to us and do what we ask. And the principle gets even stronger in person. If a salesperson can get you to take a freebie from them at a conference, you’re far more likely to listen to their pitch.

One reason this works so well is because when someone gives us something for free, we feel indebted to them. It’s a small indebtedness, but enough to make us just a little uncomfortable. So if we’re given an opportunity to do something for this gift-giver (like listen to their pitch or click on their call to action), then we’ll have paid off our debt.

So, does this really work? Well, for B2C samples it certainly does. Samples can increase sales by as much as 2000%. No wonder makeup companies give away so much.

And, reciprocity works pretty well for B2B companies, too. The SAAS company Groove did a study of 712 other SAAS companies and their conversion tactics. They found offering a free trial is a pretty darn powerful strategy:

Here’s the average site conversion without a free trial:

And here it is with a free trial:

Keep in mind that these little pushes and pulls don’t often reach our conscious minds … and that’s exactly what good persuaders want. They want to influence us just enough to nudge our behavior – but not so much that we feel like we’re being manipulated.

That’s a very important line, the difference between influence and manipulation. You absolutely want to stay on the influence side. People hate being manipulated, and if they think you’re playing them, they won’t just stop listening to you – they’ll never trust you again.

3. Scarcity

I bet you’ve heard of this one before, too. The idea is, the less there is of something, the more we want it. So when a retailer sends us a cart abandonment email that says, “Something you left in your cart is about to sell out!” you’re much more likely to take action than if they just reminded you that you left something behind.

Scarcity of stuff works well for B2C, but B2Bers can use another aspect of it: scarcity of time.

This is why countdown timers work so well.

Here’s a split-test of a countdown timer from Oli Gardner of ConversionXL . This one test increased a landing page’s conversion rate by more than 300%!

Version A

Version B

4. Simplicity (aka “Clarity”)

This isn’t a Cialdini principle, but it applies to so many situations in marketing that I have to include it.

Here’s the gist: When people are confused, they don’t act. So, if people are confused by your landing page, most of them won’t try to figure it out. They’ll just leave. If your writing is difficult to understand, most people won’t slow down and try harder. They’ll just stop reading. If your sales offer is too complex, they’ll just say no.

Anyone in B2B will be familiar with how simplicity plays out on lead generation forms. As you probably know, the more fields on a form, the less likely someone is to complete it. That’s not always true, but it’s a good general rule.

It’s not just too many form fields that can suppress response. Too many options can, as well. Unbounce tested this principle on their own webinar sign-up page. Just trimming the options down from four to three items increased their conversion rate by nearly 17%.

5. Trust.

This is another non-Cialdini principle that I’m including just … because. Because without trust, there is no sale.

Trust is one of the keys to making content marketing work. It’s also why content marketing takes time – because developing trust takes time. But as you consistently deliver helpful, accessible content to your audience, they begin to trust what you say. And so when it comes time for them to buy from you, they’ll trust what you say about your product, too.

Trust comes in many other guises, of course. There’s trust involved when a company gets good reviews, or if it wins an award. And there’s even more trust if a friend recommends a company. Word of mouth – the all-time most effective marketing tactic – is really all about trust.


Understanding what makes people tick has to be one of the most interesting topics ever. It’s hugely powerful if you can get it to work for you.

But psychology is also useful if you turn it around and assess what drives you to do things. In fact, that’s one of the key skills of the best marketers – the ability to see themselves in the audiences they seek to persuade. That empathy is really the grandfather principle of all marketing. It’s what lets us communicate in the first place.

Back to you

Do you have any favorite psychology principles I haven’t mentioned here? Give them a shout out in the comments.