The first two websites you shoud visit are Federal Trade Commission
and MSPA Mystery shopping prividors assn. The will tell you about the
legitimate and not legitimate mystery shop operators, not by company,
but by what to look for. The get the posted list of Sassie shop
clients. Sassie is a software company. If, starting out, you only
sign up with Sassie clients, you will find the software with which you
must contend, very similar and works the same way. The best software
I have found yet is Market Force if you want somehting easy to follow.