In my experience working as a commissioned sales person. For many different companies.
I always got paid this way. I got a base salary. (With a quota - i.e. $30,000 a month in sales) then a commission, and bonuses if I went over my quota in preset increments. Like if I tripled my quota I got a much bigger bonus then just doubling it etc..
My sales clients were my clients. I was supposed to handle them. If they called I was routed the call. When new clients called in or dropped in. The sales were given to the salesman on Floor time. We would switch off between us. Usually it was 4 hour shifts. Floor time basically consisted of one of us being available in the shop to handle the clients. Great time for paperwork and cold calling/setting appointments.
Now, if one of my clients dropped in. Needing help right away and the salesman on floor time had to handle it. Then I had to give up a chunk of my commission to them. For example, I was at 25% commission and if someone else handled it I only got 5% of my commission and he got his full commission. The sale wouldn't count for my quota only the other persons.
We also had a commissioned project manager that handled the clients past the intial stage. We figured out what the client wanted and wrote up the tickets then they were assigned a project manager depending on the department the bulk of the job project fell into.
If the owner had to take over a client or the Project manager had to take over our jobs. We lost out period on the sale. No commission whatsoever. We weren't doing our jobs at that point. So it was a quick way of reprimanding us.
If we didn't meet our quota 3 months in a row. We were out looking for another job.