norvigs-lawlisted

# Norvig's Law > "Any technology that surpasses 50% penetration will never double again." > — Peter Norvig, 1999 ## The core idea This is a deliberately simple, tongue-in-cheek observation about mathematics and the growth of technology. If a technology already reaches more than 50% of its target market, it cannot double again — because doubling would require more than 100% penetration, which is impossible. More broadly: growth rates that sound impressive early in adoption become mathematically constrained as penetration increases. The "doubling" narrative that works at 1% doesn't work at 51%. ## Why this matters **Evaluating growth claims:** When someone says "smartphone adoption will double in the next 5 years," check the current penetration rate. If it's already at 60% of the relevant population, doubling is impossible. Claims like this reveal either innumeracy or deliberate misdirection. **Understanding S-curves:** Technology adoption typically follows an S-curve: - Slow initial growth (early adopters) - Rapid growth through the middle (majority adoption) - Flattening as the market saturates A lot of projections implicitly assume you're always in the middle "rapid growth" phase, even when you're clearly approaching saturation. Norvig's Law is a quick check: where are we on the S-curve? **Skepticism about market reports:** Analyst reports and press releases frequently cite impressive percentage growth rates for technologies that are approaching saturation. If a tec