Are you a 'Secret Shopper'?

If so, how did you get involved ? The lure of easy money? Do you get a little thrill when someone passes/fails your shop? Do you time your shop for when its busy, or just whenever? Do you know what happens when someone passes/fails? Do you favor a particular person/place?

I will confess; I consider secret shoppers the bane of my already thankless job. I just want to know what you get out of it, how does it work for you.