Have any of you accepted a shop and then complete it and realize how obvious the mystery shopper is? One store I completed you must use the restroom. The restroom is only open if you ask a staff member to use it. As soon as I come out, the sales people are all over me! Another shop you must make a purchase but use an expired credit card or enter the pin wrong. Can we be more obvious? I don't complete either of these shops anymore :-)
Well, I guess it all depends on how well can a shopper "act it out" and make the situation sound believable. Although I do think that if multiple shoppers come to the same store in the same month and present the same (rare) scenario, it can get a bit suspicious - but MSPs keep this in mind when setting up scheduling rules and limitations, to make sure the shopper's aren't revealed.
I never really had an issue...but I spent a lot of time in retail, including LP work, so maybe I just know how to blend in better. I was talking with a friend who I got in some mystery shopping and she was "I feel so awkward, i'm taking pictures, they KNOW i'm a shopper" and I was "You send me pictures of stuff you're buying ALL the time, how is this any different???" I've had to half bend back (and i'm like 6'3" with a bouncer build) like I was doing limbo to take a picture of a bottom shelf while IN the check out lane, not a single person paid attention. The world is pretty obvious! :)
Yes, there are some shops where the scenarios could use some upgrading. However, most of them actually do work out okay.
Buying small amounts of gas: For most of these shops, you pay at the pump (unless you are in Oregon or New Jersey, where it is illegal to pump your own gas) and the attendant never knows who much you personally spent on gas. Or, even if you do, you then ask to use the restroom (a required part of the shop) and it makes your cover: You didn't really need gas, you needed to use the restroom. However, you got a small amount of gas so that you could be a customer and,therefore, had the right to use the restroom. If you are only doing one gas station, you can always just fill up your tank. Most of us have to fill our tanks about once a week, anyhow, so it's not like we are spending more than we would otherwise.