Possible job offer

So, I had a meeting with a former vendor from my last job. It definitely sounds like something I could do a great job at and it's not as far of a drive as the last job. The only thing is I'm gathering it's a commissioned job and I'm just not sure I'm comfortable with that. I'm wondering how I can realistically expect it to work. I can't think of anyone I know who makes a living by commission and I don't want to get sold by the potential employer. Do any of you have any advice?