They won't drop you, but you won't be paid.
I picked up a Presto 'prepaid' recommendation shop at Walmart since I was there grabbing a prescription. The directions state to ask an employee for their recommendation on a prepaid phone. It was a Saturday in a busy Walmart... the only thing the employee did was ask me which phone I wanted unlocked from the case. When I said I wasn't sure she told me to come get her when I decided. She went on to help the next 10+ people in line.
I did not get paid because I did not get a recommendation.....
I only pick up these kind of shops if I'm already there, knowing if they pull this type of crap I'm only out a few minutes of my time.