In the case of this particular shop, my understanding is that the client requires drug testing and background checks on all employees, merchandisers and miscellaneous folks who are not customers in the store. When this shop was originally discussed, the MSP was offering more money for it and implying less baloney than eventually was required. In my area it looked to be a decent gig alternating months to visit different locations in my immediate area (one 5 miles away, one 12 miles away) and even being able to pick up slightly further locations on either an emergency basis or a regular basis should the shops turn out to be a gift. We put up with a fair amount of malarkey and so although the testing and background check were an invasion of my privacy, I could live with it. Plus it basically meant more paperwork as the MSP was going to pick up the tab for the testing and background check with the completion of the first job and it would not need to be done again.
Maybe these have worked well for some folks. The initial scuttlebutt I heard was that they were a huge mess. By now I'm sure they have those chinks worked out of it. I see them advertised from time to time, which tells me folks have dropped out of the program for whatever reason. But the price tag on the job is $20 less than they originally were going to pay for them and they only dropped the price when they actually scheduled in response to indications of interest.