01
Growth
customers_next = customers_now + acquired − churned
Growth is the interaction of acquisition, activation, retention, expansion, and referral.
02
Measure the Rate
YC's Paul Graham has emphasized measuring startup progress through growth rate rather than only absolute user counts.
weekly growth = (current users − previous users) / previous users
03
Growth Loops
- Referral loops.
- Content loops.
- Network effects.
- Marketplace liquidity loops.
- Product-led acquisition.
- Usage-generated content loops.