Concept
Network Effects
Network effects occur when a product becomes more valuable to each user as more people use it, so growth itself strengthens the product and makes it harder for rivals to catch up.
A phone nobody else owns is useless. A messaging app everyone uses is hard to quit. That is the whole mechanic: each new user adds value for existing users, and that value attracts more users. In Zero to One, Peter Thiel names network effects as one of the few sources of lasting monopoly, alongside proprietary technology, economies of scale and branding. This ties directly to being the last mover. A company is worth the cash it earns far into the future, and network effects are a rare edge that grows stronger with time instead of eroding. The hard part is the start. A network of ten users is worth almost nothing, so launching big rarely works. Thiel's advice is to begin with a market small enough to saturate, then expand. Density matters more than raw totals, and the effect also runs in reverse: when users leave, value drains fast.
A real-life example
A founder builds a marketplace connecting tutors with parents. She launches citywide with 40 tutors scattered across 30 neighborhoods. Parents rarely find anyone nearby and stop opening the app. She restarts in one district, putting the same 40 tutors within walking distance of three schools. Parents now find a match in minutes and tell other parents. New tutors sign up because that is where the parents are. She adds a second district only after the first is saturated.
How to use it
- 1Ask whether each new user makes the product better for existing users. If not, you have a product that grows, not a network effect.
- 2Define the smallest network you can fill completely, such as one campus, one neighborhood or one profession. Dominate it before expanding.
- 3Track density, not just totals. Measure how fast a new user finds value: a match, a reply, a seller. If that time shrinks as you grow, the effect is real.