Double Jeopardy Simulator
Explore how the Double Jeopardy law emerges from simple probability. Adjust market shares and see how larger brands naturally achieve both higher penetration and slightly higher loyalty—without any "brand magic" or differentiation.
The Pattern: Brands with higher market share have more buyers (penetration) AND those buyers are slightly more loyal (share of category requirements). This isn't about brand love—it's pure mathematics.
Simulation Parameters
5%Brand B: 30%95%
Key Metrics Comparison
| Metric | Brand A | Brand B | Ratio (A/B) |
|---|---|---|---|
Market Share | 70.8% | 29.2% | 2.42× |
Penetration | 97.5% | 64.1% | 1.52× |
Avg Purchases/Buyer | 2.18 | 1.37 | 1.59× |
Loyalty (SCR) | 72.6% | 45.6% | 1.59× |
SCR (Share of Category Requirements): The percentage of a buyer's category purchases that go to this brand. Higher SCR = higher loyalty.
Metrics Comparison
Share vs Penetration & Loyalty
Key Insights from the Simulation
📊 The Pattern is Clear
Brand A with 70% market share has 1.5× the penetration of Brand B, but only 1.59× the loyalty. The penetration advantage is much larger than the loyalty advantage.
🎯 Growth Implications
To grow market share, Brand B needs to focus on increasing penetration (getting more buyers) rather than trying to increase loyalty among existing buyers. The math shows penetration drives growth more effectively.
Note: This Monte Carlo simulation holds brand preference constant across all purchases. The Double Jeopardy pattern emerges naturally from this simple assumption—no brand differentiation required.
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