story
https://steveblank.com/2010/01/25/whats-a-startup-first-prin...
"A startup is an organization formed to search for a repeatable and scalable business model."
Maybe you see "scalable" and think "to a billion users". I see "scalable" and think "sustainable over the long term".
I think a small business is when you know the business model can work and have moved on to long-term execution. Until then you are a startup.