I do shops for them occasionally. I hadn't been paid for the first few shops I performed when I received an email about open shops. I replied saying that I would be willing to pick up a shop or two if I was paid for my previous shops. I was paid that day.
Recently, I had some unpaid shops. I picked up a couple emergency shops and, without my asking, received a notice af payment to my PayPal account.
I don't much like having to babysit payments, but I do get paid by them.