It's not even about sponsorship or prize money.
In whatever segment of running you are in (HS, college, age group, professional, masters), if you are capable of being competitive and maybe even win races in your class, then you are by definition not a hobby jogger.
Hobby jogging is relative. If you are the number 1 8th grader in your state, your times may pale compared to a pro runner, but you certainly are not a hobby jogger. Same goes for the number 1 freshman in college, etc.