You start small so you can be the most valuable, most relevant, and most useful to a small group.
You start small so you can give the most attention to each individual person.
You start small so you can wow a small group instead of bore a larger group.
You start small so no-one can compete with you, not even the big fish.
You start small to build powerful early sense of community.
You start small to establish social norms and setup the right traditions.
You start small to keep expectations reasonable.
You start small so future newcomers will see a friendly, thriving, group they join.
You start small so you can run tests, make mistakes, and find out what works for you.
You start small because it’s more reliable than starting big.
You start small because you grow faster.
You start small so you can get the concept right before wasting your first impression.
You start small so you can get some great stories to tell future members (and core stakeholders)
You start small to showcase results as quickly as possible.
If you’re in doubt, start small. If you’re not in doubt, start small anyway.