I did mystery shopping for a couple of years. It was a good gig until the gas prices skyrocketed. That was back in 2003 or 4.
Don't pay anyone anything to mystery shop; not some company that's going to set you up with shops and not some person who is going to show you the ropes.
In the beginning, I took the jobs where I didn't shell out money such as book stores, banks and cell phone companies. Those jobs were mostly about signage and responses to specific questions.
There were jobs that required no writing but picture taking instead (gas station bathrooms) and fill in the blank/true false responses
Some of the jobs I took where I did spend money but was reimbursed included services for my car, hotels, car rentals and airfare.
As your reputation improves so will the money and the types of jobs you're able to get. The feedback required will become more difficult and extensive as the money gets better.
Some companies require a paypal account.
You'll be an independent contractor, responsible for your own taxes.
Companies generally do not solicit unknowns for jobs. They don't mass mail, email or otherwise. They will contact you if you have gotten good reviews for your shops, Or if you've put your name on lists, somewhere.
I googled the company you asked about and found only one bad review. That was from 2009.
http://www.ripoffreport.com/r/Premi...pper-Survey-Division-Premier-Mystery-S-495498
Google brought up other information. I didn't really read any of it.
I belonged to several online groups and forums where jobs were posted and reviews of companies and specific jobs were discussed.