The 6, 7, 8, or 9 Key Principles of Persuasion: What Works for You?

Dr. Robert Cialdini’s Influence: The Psychology of Persuasion is to marketing communications what The Joy of Cooking is to, well…cooking. It’s a classic. If it’s not already on your shelf, it probably should be. Dr. Cialdini, a respected social psychologist, made his mark by unpacking the science behind what gets people to say “yes”—and how we can use that understanding ethically and effectively.

In his book, he outlines seven key principles of persuasion that can be applied to all kinds of communication, including branding. They don’t all work in every situation, and they shouldn’t be used to manipulate. Cialdini is very clear about that. The goal is to help people see your message in a way that resonates—clearly and compellingly.

I think six of the seven principles are rock solid. I have some questions about the seventh (Unity), and I believe there are a couple more that deserve a spot on the list. So below is a breakdown of six to nine persuasion techniques you might want to keep in mind when developing your brand or marketing strategy:

1. Reciprocity

When you give people something of value—whether it’s a sample, a kind gesture, or helpful advice—they’re more likely to return the favor.

Example:

We helped a health system develop a free household health guide that was mailed to homes in its service area. Nearly a decade later, people still mention they have this handy guide. That brochure made a lasting impression—and created goodwill that stuck.

2. Scarcity

People want what they think they might lose. That’s why phrases like “limited-time offer” or “only two seats left” work so well.

Example:

If you’ve booked a hotel through Expedia, you’ve seen messages like, “Only 1 room left at this price.” That’s scarcity nudging you to act fast.

3. Authority

We tend to trust experts—whether it’s NASA, the Mayo Clinic, or even the Navy SEALs. If professionals use it or recommend it, we’re more likely to listen.

Example:

Remember the classic toothpaste line? “Four out of five dentists recommend Crest.” It’s been effective for decades because it taps into our trust in expert opinion.

4. Commitment & Consistency

Once people make a small commitment, they’re more likely to stick with it—especially if it aligns with how they see themselves.

Example:

The ASPCA asks for just 63 cents a day. It’s a tiny commitment, but once someone signs up, they’re likely to keep giving—because they now see themselves as someone who supports animal welfare.

5. Liking

We’re more likely to support people and brands we like. It’s that simple.

Example:

Dove’s “Real Beauty” campaign won hearts by using real, diverse women instead of airbrushed models. It made the brand more relatable—and more likable.

6. Social Proof (a.k.a. Consensus)

When in doubt, we look to others. If a product is popular or widely endorsed, it must be good, right?

Example:

Amazon does this brilliantly with their star ratings, reviews, and “Amazon’s Choice” badges. You’re not just buying a product—you’re joining the crowd that already loves it.

7. Unity (debated)

This principle suggests that people are more influenced by those with whom they share a strong sense of identity. While it overlaps with Social Proof, some brands effectively utilize it by tapping into shared values.

Example:

Patagonia’s environmental activism and Ben & Jerry’s outspoken social advocacy make people feel like they’re part of something bigger—not just customers, but fellow changemakers.

8. Contrast

We make decisions through comparison. Showing the “before and after,” or what’s gained vs. what’s lost, can make a product’s value crystal clear.

Example:

Airbnb often contrasts its spacious, homey experience with traditional hotels. The result? Airbnb feels like the better, more “authentic” choice.

9. Discomfort / Distress

People are hardwired to help those in visible distress—especially if the suffering is vivid, personal, and solvable. This isn’t for every brand, but when used appropriately, it’s powerful.

Examples:

• Save the Children shows images of children in crisis to spark compassion.

• Truth Initiative and anti-smoking campaigns use graphic, real-world consequences to stop risky behavior.

• NHTSA uses gripping crash reenactments to discourage distracted driving.

We use these principles like a checklist when helping brands tell their stories. Not every technique fits every brand—obviously, a luxury hotel doesn’t need to distress you into booking a stay. But if you’re a nonprofit raising awareness about opioid abuse, creating discomfort might be the only way to wake people up.

These aren’t tricks—they’re tools. And when used ethically, they can make your message stronger, clearer, and more human.

It’s worthwhile to review your brand to see how many of these techniques you're using and which ones you should be using. Let me know if you’d like assistance in figuring out which principles work best for your brand.