I hate this so much it. It makes me want to cuss out any hiring manager who does this. You aren't hiring for a job, you are looking for a sucker to agree to work without pay unless a sale is made. Why spend time on something for a company that may or may not be a waste of time. And yet base f**king salary and commissions being a bonus isn't feasible? Why? That's how most sales jobs of that nature work.
We are adults not girl scouts. Why bother asking for a degree if the job can be done without one. Stuff like this is why “there's so many jobs!” Is a bs lie. There's a lot of scams and false job postings.