Sales positions are paid a draw against commission, with no base salary. Most territories have a good book of existing steady business, so that alone isn't a bad setup.
The big risk you face from a commission payment standpoint is leadership shifting things around.
In the time I was there, they took away product lines, and changed a major industry segment to having dedicated sales people - they took away from your existing book of business, without increasing commission rate, meaning you get paid less.
And to be clear, these changes happened across the company, not to select salespeople as punishment for underperforming.