Key Takeaways

  • Cleo dramatically differentiated itself in the staid financial sector by infusing personality and humor, a strategy founder Barney Hussey-Yeo credits with driving engagement.
  • Early on, Cleo went as far as hiring 30 female comedians to write all user-facing copy, directly addressing the AI's intelligence limitations at the time.
  • This commitment to a distinctive tone wasn't just a branding exercise; Hussey-Yeo saw it move critical metrics like monthly active users (MAUs) and revenue within the first three to six months of building the business.
  • Cleo has since evolved to use large language models (LLMs) to personalize the tone of voice, adapting it based on individual user demographics and financial health.
  • The core insight: in any "boring" or stressful industry, taking the inverse position—making the experience fun and approachable—is a clear differentiator that few founders actually execute.

The Unlikely Punchline in Your Bank Account

Traditional financial institutions speak with the grave seriousness of a funeral director. Every interaction is dry, factual, and designed to convey trust through a lack of emotion. But what if that's exactly the wrong approach? Cleo founder Barney Hussey-Yeo saw this whitespace and launched an AI financial assistant with a radical idea: make money management fun, even funny.

He noticed something counter-intuitive: humor and money, a notoriously stressful subject, “actually go together weirdly well which no financial institution uh spoke on to all your lawyers and your your executives.” This wasn't just a hunch. It became Cleo's defining feature, a personality that stood out in a sea of identical, serious apps. John Collison, Stripe's co-founder, quickly picked up on this, noting, “I get the impression that for you guys the personality of uh Cleo and how it interacts with you is a big part of the differentiation.”

From 30 Comedians to Personalized AI Sass

Building that personality from scratch was no small feat. Before today's powerful LLMs, an AI chatbot couldn't deliver the nuanced wit Cleo needed. So, Hussey-Yeo employed a decidedly analog solution: “Do you know what's funny back in the day because it wasn't as intelligent. We had to really rely on humor. So we had 30 female comedians on staff.” Imagine the daily stand-ups for those writers. This human-centric approach ensured every interaction had a distinct, engaging voice.

As AI evolved, so did Cleo's strategy. Today, LLMs power the personalization of Cleo's tone. This means the AI can tailor its humor and personality not just generally, but specifically to a user's demographics and financial health. A young user struggling with debt might get a different, more empathetic-yet-still-witty tone than a financially stable older user. This blend of human-honed humor and AI-driven personalization creates an experience that's both unique and deeply relevant.

Brand Personality isn't Fluff; It's a Growth Engine

Some founders view brand personality as a 'nice-to-have,' something you tackle after product-market fit. Hussey-Yeo's experience at Cleo flips that script entirely. He learned quickly that a strong, engaging tone directly impacts the bottom line. “Being funny, being concise, writing well, all these things move our MAUs, it moves our revenue.” This wasn't some abstract marketing theory; it was a measurable driver of business growth from the very beginning.

Within the first three to six months of building Cleo, the team understood that “the brand and the personality and the tone of voice mattered a lot.” Barney Hussey-Yeo believes the key is taking an "inverse position" in any industry perceived as boring or complex. Most financial apps aim for "really simple, really boring." Cleo went "really fun." It's “such an obvious thing to say, but I think like how many founders do you see actually take that?” Few, he argues, and that's the opportunity.

What to Do With This

Audit your product's most "boring" or stress-inducing customer touchpoints this week—think onboarding flows, error messages, or billing notifications. Identify 3-5 places where your communication is purely functional. Then, spend two hours rewriting those messages with a deliberately unconventional, humorous, or highly personalized tone, taking Cleo's inverse position. A/B test these new versions against your current dry defaults to see if a little personality moves your own key metrics.