I would guess some people who had a profitable side project turned it into their primary source of income. Someone making $1000 a month from a side project can'

I would guess some people who had a profitable side project turned it into their primary source of income. Someone making $1000 a month from a side project can't afford to quit their day job. Someone making $10k a month from a side project can probably afford to quit their job and make the side project their primary focus.