Double Jeopardy in marketing: Why market leaders win twice

The Double Jeopardy law is one of the most robust empirical generalizations in marketing science. It reveals that larger brands systematically enjoy two advantages: they have more buyers (higher penetration) and those buyers are slightly more loyal (higher share of requirements). This pattern emerges purely from probability mechanics, not from superior brand positioning or emotional connections.

1. Lower Penetration: Fewer people buy them 2. Lower Loyalty: Those who do buy them, buy them less often

Conversely, market leaders benefit from both higher penetration AND slightly higher purchase frequency. This creates a compound advantage that's difficult to overcome through traditional loyalty-focused strategies.

| Brand | Market Share | Penetration | Purchase Frequency | Share of Requirements | |-------|--------------|-------------|-------------------|---------------------| | Coca-Cola | 40% | 68% | 3.2/year | 59% | | Pepsi | 25% | 45% | 2.8/year | 55% | | Store Brand | 10% | 22% | 2.1/year | 45% | | Craft Cola | 2% | 5% | 1.6/year | 32% |