Oh yeah? I did shops for them 8/1 and have not been paid yet, and last month I had to call them and write 3 times before I got paid, and it was well over 60 days..The shops are good but some times the reimbursement amount is the same as the shop fee and you have to wait and wait for them to pay.
Sites such as JobSlinger are great places to find out which mystery shopping companies are actually posting shops in your area. So sign up with those companies that come up on a local search in these types of sites first. Then use the list on Volition to sign up for the rest. You never know when any of these companies might happen to get a contract in your area. If you're already signed up, you'll be the first to know.