[Case 02]
StoneClub - Rewards Program
De-risked a paid rewards model before launch by validating low differentiation (39% flat interest; 58% competitive overlap).
[Industry]
Fintech
[My Role]
Product Designer
Context
At Stone, a Brazilian SMB-focused fintech, the goal was to increase adoption and retention across Card and Reserve through a paid benefits program.
The strategic hypothesis was that a subscription-based rewards model - combining cashback, higher yield on balances, and fee-waiver conditions - would drive recurring engagement, deepen product usage, and reduce churn.
Problem
The model assumed customers would pay for differentiation - but early signals suggested differentiation might not exist.
Before build or rollout, four unknowns required validation:
Real willingness to pay (beyond surface interest)
Competitive overlap
Eligibility feasibility at scale
Behavioral ability to consistently hit waiver thresholds
What I Did
Led concept test (n=1,514)
Ran 10+ usability sessions
Analyzed eligibility constraints
Mapped competitive benefit landscape
Defined MVP-ready cohort (21.8K customers)
Structured segmentation logic for experimentation
Outcome
The concept test (n=1,514) showed the subscription model had low structural differentiation in a saturated cashback market:
• 39% flat interest across pricing tiers
• 58% competitive benefit overlap
• Limited behavioral feasibility to sustain fee-waiver thresholds
This materially weakened the model’s revenue defensibility before rollout.
The initiative was later deprioritized in favor of a Visa cashback campaign with stronger short-term acquisition leverage.
Business impact
• Preserved capital allocation by preventing investment in a low-defensibility subscription model
• Reduced fee-sensitivity churn risk
• Avoided internal cashback cannibalization
• Reused insights to shape credit-led growth bets
What I Learned
Customers anchor value to predictability, not to feature count.
The subscription only felt attractive when the fee waiver felt guaranteed.
When framed as conditional and uncertain, perceived value collapsed - even among cashback-oriented users.
Differentiation in fintech is less about stacking benefits, and more about reducing ambiguity.
