Building Products People
Love Fanatically

Jag Duggal

Chief Product Officer, Nubank

FORMER GOOGLE · FACEBOOK

The Scale

Nubank's Staggering Growth

"80% to 90% of Nubank's growth is through word of mouth. We are not trying to be incrementally better, we are trying to be fundamentally different."

Bigger than Coinbase, Robinhood, Affirm, SoFi combined
More customers than Bank of America operating only in 3 Latin American countries
80–90% of growth driven purely by word of mouth
No massive marketing spend; customers become advocates naturally

Framework

The Five Values That Drive Fanatical Loyalty

Customers love us fanatically: The North Star. Every decision, every trade-off, measured against this.
Hungry & challenge the status quo: Bias toward disruption, never satisfied with "good enough."
Build strong, diverse teams: Talent and diversity as competitive moats.
Pursue smart efficiency: Profitability mindset baked in from day one.
Think & act like owners: Do what's right even when no one's watching.

50%

Sean Ellis score target (vs 40% global)

70–90

NPS scores across markets

The cultural filter"We want our customers to love us fanatically" isn't just a wall poster, 80–90% of Nubank employees can recite all five values on the spot. This is real.

The Measurement Obsession

Sean Ellis Score: The Gate to Growth

The question: "How disappointed would you be if this product disappeared?" (scale: not / somewhat / very disappointed)
The threshold: 40% "very disappointed" globally; Nubank raised it to 50% for Brazilian cultural politeness adjustment
When to use: Post-launch, every new product, before deciding to scale
Beyond Sean Ellis: NPS tracked obsessively; even a 1–2 point dip triggers investigation and iteration
Churn matters: Retention is the foundation of viral loops. A leaky bucket kills word-of-mouth growth.

Amazon mock press release

Before a single engineer writes code, explain to the customer, in two paragraphs, why they should care. If you can't justify it, there's still work to do.

Design reviews that ask the hard question

"Is this great enough?" Not just good. Not incremental. Is it great? Will customers tell their friends?

The Strategy Playbook

Strategy is Clarity. Execution is Speed.

Strategy ≠ vision. It's a coherent plan: specific customer, specific problem, specific advantage.
Nubank's original strategy was laser-specific: millennial, middle-class, urban Brazilians + no credit fees + no branches = digital-first disruption.
Strategy informs focus. Bad strategy multiplied by great execution = zero. Good strategy multiplied by good execution = wins.
Concentration builds wealth (for startups). Diversification preserves it. Pick focused bets, not hedges.

Kevin Systrom's mantra"We may not be right, but at least we are clear." , A clear strategy that's wrong is easier to course-correct than a muddled one.

Contrarian

Silicon Valley Myths Jag Rejects

✗Execution is everything, strategy doesn't matterINSTEAD →✓ Great execution on bad strategy = waste. Legendary companies got strategy AND execution right. Most failures had neither.

✗Be incrementally better than competitorsINSTEAD →✓ Only fundamentally different products make people want to tell their friends. Incremental improvements are invisible to word-of-mouth.

✗Diversify your bets to reduce riskINSTEAD →✓ Startups need concentration. Hedging is appealing but it kills focus. Desperate companies make focused bets and win.

✗Marketing spend drives consumer growthINSTEAD →✓ If you build product people love fanatically, they become your marketing. Nubank grew 80–90% through word-of-mouth, keeping marketing to a small portion of investment.

Based on Jag Duggal's episode on Lenny's Podcast. All ideas on this page are from the episode.Watch on YouTube

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