I ask this to myself: what's the limit?.
A company with millions on revenue still being called startup.
Could somebody please help me understand why?
I would prefer to call Dropbox as mid-sized company with momentum
I'd say it's more to do with number of employees. 37signals would be considered a start-up by most people while Facebook is definitely not a start-up
I would not think of 37signals as a startup because they're not focused on growth, in search of a business model, in search of funding, or going through other startup-specific issues.