“You acquire 100,000 this year and they're still there next year, and you put 100,000 on top of that — by year three you just continue to grow this pie of people who are very sticky in the product.”

Long-term local retention stacks cohorts into compounding revenue layers

If locals genuinely flatline on churn (like long-term Netflix or Spotify subscribers), each acquisition cohort becomes a permanent revenue layer. Year-over-year you do not replace subscribers — you stack them. This is the mechanism behind the extreme multiples CSS companies command: investors are pricing the right to that stacking behaviour, not just today's ARR.