Business Writing 2017-10-25 00:00

What Makes Customers Say "Yes": The Psychology of Persuasion

As a copywriter, if you only ever read two business books in your lifetime, read these two:

  • Influence: The Psychology of Persuasion by Robert Cialdini
  • How to Win Friends and Influence People by Dale Carnegie

Cialdini uses over 35 years of evidence-based research on influence and persuasion and a 3-year program to study what moves people to change behavior. He is the thought-leader and expert on persuasion. And Carnegie is the master of selling yourself or anything else to just about anyone. If you want to be an in-demand copywriter, you need these two resources more than any others.

Let's look at the 6 founding principles of influencing and persuading someone to click through, sign up, or buy something.

  1. 1. Reciprocity
  2. 2. Scarcity
  3. 3. Authority
  4. 4. Consistency
  5. 5. Liking
  6. 6. Consensus
  7. Conclusion

1. Reciprocity

Reciprocity comes in the form of social obligation. What we mean by social obligation is when someone invites you to a party, you feel obligated to invite them to your party at a later date. Or if the server in a restaurant goes above and beyond and gives you something for free like a mint, you feel obligated to tip him or her well.

Think of a time at work when a colleague had your back. Did you feel beholden to pay him back somehow? This is the gist of reciprocity. Now think of all the "free" content on the internet you can get by simply exchanging your name and email address. It's social obligation that forces you to offer your prized personal information so you can get the valuable content. They're giving you something for free so you feel it's only appropriate that you give them what they want.

2. Scarcity

How many times have you purchased something that's on a great sale for a short time? Advertisers use "while quantities last" and "for a limited time" verbiage to trigger the scarcity principle.

Think of when British Airways announced over 15 years ago that they were discontinuing the Concorde's London to New York flight for economic reasons. Sales the next day skyrocketed. Why? Nothing had changed; it was still the same flight with the same services on the same plane. But it was suddenly a scarce commodity. People wanted in on it before it was gone.

3. Authority

If you can get a celebrity or someone of great respect and admiration to endorse your product or service, it's almost the golden standard. We respond to credible, knowledgeable experts.

Think about your doctor's or dentist's office. Does he or she proudly display diplomas and other certifications or associations on the office walls? If he's smart he does, because patients are more likely to follow a doctor's advice when credentials are prominently displayed.

An interesting study was conducted in a real estate agents' office. When calls came in from someone with a property to let, the receptionist would mention an agent's credentials and expertise before transferring the call. For example, he might say, "Letting? Let me connect you to Brandy. She has over 20 years of experience letting properties in your area." The result of the study was a 20% rise in the number of appointments and a 15% increase in signed contracts when using this expert introduction.

4. Consistency

If you've already said, "yes" to something of lesser importance, something easy to agree to, you're more likely to agree to a bigger ask later on. Let's look at an example of this.

A study performed in two similar neighborhoods targeted a Drive Safely campaign. The purpose was to encourage neighbors to put a big, ugly sign in their front yard to support the campaign. In the control neighborhood, very few people were willing to put this ugly sign on their property. In the other neighborhood, however, they saw a 400% increase in those willing to put the unsightly billboard in their front yard. Why? Because 10 days earlier, these neighbors had agreed to place a small postcard in their front window to support the Drive Safely Campaign. That initial commitment led them to consistently agree to the larger, ugly sign.

5. Liking

What causes one person to like another? Psychology tells us there are 3 important factors. We like people who are like us, we like people who pay us compliments, and we like people who cooperate with us towards mutual goals.

How could we use this online? Well, have you ever been drawn to an advertisement that said something like, "Like you, we love __, too!" And you automatically read on to see what they have to say. Then they share some personal information and you think, "holy cow, I do the same thing." Now you're hooked. (As a writer, what always gets me are the articles or posts that talk about journals and pens and the other crazy habits that let me know I'm not alone in this world.)

So using the liking principle, find areas of similarity, offer some genuine compliments, and look for mutual goals.

6. Consensus

If you're uncertain, what's the first thing you do? You look to the behaviors and actions of others to help you determine your own. That's why customer reviews on Amazon are so potent. If you think the majority of others out there liked something on Amazon, you're more likely to purchase it, right?

A great experiment in the hotel industry verified the principle of consensus. To reduce their carbon footprint, hotels left cards in the bathrooms to persuade guests to reuse their towels and linens. They found that 35% of guests would reuse towels when they considered environmental protection.

However, one hotel reworded their cards. Instead, they printed "75% of people who check into our hotel reuse their towels to help us reduce our carbon footprint." This led to an additional 33% increase in towel reuse. When guests saw others were already doing it, they didn't need much persuading.


Hopefully, this short and sweet compilation of the 6 principles of persuasion has given you ideas to use in your own copywriting. If you want to break out from the crowd, use these principles when persuading someone to click through, opt-in, or buy something. You'll be surprised at the influence and persuasion you'll wield over others—in an entirely ethical way.

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