How one hotel towel experiment cracked a code on persuasion — and what it means for YOUR product messaging

Behavioural psychologist Robert Cialdini wanted to figure out which hotel towel signs actually worked.

Three versions.

Same goal.

Wildly different results:

“Help save the environment and reuse your towels” → 35% compliance

“Nearly 75% of our hotel guests reuse their towels” → 44% compliance

“Nearly 75% of hotel guests who stayed in this room reused their towels” → 49% compliance

The winning approach was NOT about saving rainforests and cute animals, but about tribal belonging.

The most persuasive message implied: “People exactly like you — who slept where you’re sleeping — are doing this too.”

Same data. Hyper-specific context. 40% better results!

This is really how our ancient brain processes social proof.

And we don’t simply want to know what generic “other people” do. We want to know what people like us do.

“Customers love our product” feels generic.

“CFOs at mid-size tech companies say this saves them 6 hours weekly” feels personal, and specific.

“Working Strat players who tried a BzzzzKill call it a game-changer” hits different than “guitarists love it.”

The specificity here signals: 

This is for people exactly like YOU, facing exactly YOUR situation.

In I Need That, I explain how our dog brain constantly scans for tribal identity cues. The more specific the tribe, the stronger the connection.

The specificity strategy: Replace broad social proof with laser-targeted testimonials.

Instead of “thousands of customers,” try “hundreds of [specific role] at [specific company type].”

Rather than “users report success,” share “people who [specific situation] see [specific outcome].”

The magic happens when prospects think: “That person is basically me.”

You probably want to revisit the way you target the messaging, and it’s worth doing.

What’s the most specific tribe your product serves — and how can you make that tribal identity crystal clear in your messaging?

Forward this to someone crafting ad messaging, or reach out to my team of product marketing strategists at Graphos Product.