Here are a couple of new Mystery Shops that are going on right now.
Service Performance Group has Mattress Giant Shops available in many cities. The pay is $18.00 and there is no purchase required. Attention to detail and timely reporting are a must. You must fill out the required agreement to sign up for their email job boards, but it is a good company to work with.
Bare International has quite a few shops available. Everything from Health and Fitness Shops with LA Fitness or Ballys to restaurant shops with Chili's. This is a great company that I have done several shops with.
Most companies assign shops based on a rating system based on previous shop activity. Most restaurant shops require at least a shop rating of 5.
Good luck and have fun. As always there is no fee to sign up to shop with any of the companies that I work for.