I have found all of the secret shoppers and that is what I'm sharing with you today.
first of all you will have to be lvl 25 or above and in Marley bone in order to learn them all
I'll get pics of them as soon as i can.
first secret shopper is in colossus Blvd she is located in the hut right across from Mindy pixie crown
the second shopper is in krockatopia on the roof of the shop on the island that is only available every hour to hour and a half
the last one is in Marley bone in digmoore station right after you exit the elevator it is a stair case by the mayor go down the stair case and there is the secret shopper.

last but not least the secret shoper badge. go inside the building the krockatopia secret shoper is standing on run up and down the carpet 4 times and that is how you get the badge.