Network Effects
The phenomenon where a product or service gains additional value as more people use it. The network itself becomes the moat.
The Idea
A phone is useless if you’re the only one who has one. The value of the network grows with each new user — sometimes linearly, sometimes exponentially (Metcalfe’s Law: value ∝ n²).
Types
- Direct: More users → more value for all users (phone, messaging apps)
- Indirect: More users → more complementary products → more value (iOS → more apps → more value)
- Two-sided: More buyers attract more sellers, and vice versa (marketplaces like eBay, Uber)
- Data network effects: More users → more data → better product → more users (Google Search, Netflix recommendations)
Examples
- Social media: Facebook’s primary value is that everyone else is on it
- Marketplaces: Amazon’s seller base attracts buyers; its buyer base attracts sellers
- Language: English is valuable partly because so many people speak it
- Bitcoin: Security increases with the number of miners
Critical Questions
- Is the network effect local or global? (Uber is local by city; Facebook is global)
- Does the value scale with n or n²?
- Are there diminishing returns (congestion, noise)?
- What happens when the network tips — or unravels?