The demarcation point for free tier was collaboration, not capability.

Most free tiers strip out enough features to drive you to paying for a product. We took the opposite approach: All the features work for free for ever, but for only one user. Then you pay for a second user who wants to join the workspace.

The trade-off is genuine. We have a large solo user base and most of them will never pay. Our free-to-paid ratio is less than 2% which would scare an investor.

What we got from this: people talk about our product without an exception. About a third of the new signups say their friends recommended us.

I don’t know yet whether this can be sustained at scale. Have you run a generous free tier for more than two years and could economics work there? What was the first thing that broke?