If you had asked which MSCs shop grocery stores, you probably would have gotten some answers. You have identified the client, even if you did not name them. To answer you now would be a violation of the contract the shopper signed with the MSC.
Equal rights for others does not mean fewer rights for you. It's not pie.
"I prefer someone who burns the flag and then wraps themselves up in the Constitution over someone who burns the Constitution and then wraps themselves up in the flag." -Molly Ivins
Never try to teach a pig to sing. It's a waste of your time and it really annoys the pig.
Now that someone has named Meijer, responding would be an ICA violation regardless of what the OP edits.
It might help the OP more to suggest that she ask, in another thread, for companies who perform grocery mystery shops. She likely will get a lot more company names than she wants, but she is likely to get some. Asking for specifics and for locations is difficult. Although we help each other on the forum, we are all running our own businesses and we are competitors. Someone is performing those shops right now in specific areas, and they are unlikely to be willing to offer up their list of clients so someone else can grab the assignments. LeslieKay's post illustrates that, and I agree I would not provide specifics to someone because I am a competitor with others in my geographic area.
Signing up with more companies is the way I would go. Also, watching Job Boards might help. And there's no problem with asking "Who shops grocery stores?" and signing up with all the companies that are listed who shop grocery stores.
These are my bread and butter each month and I only get maybe 25% of what gets posted. I've resorted to doing Lowell, Greenville, Ionia... 30-40 miles from home just to get these - of course with bonuses. Luckily, I've got a good relationship with the Director over these so I do get some of their other fun but weird shops, plus the largest mass merchant in the country is thru them, They pay like clock work and usually a few days early. It's a great gig.
It sounds like a great gig. And it sounds like it is worth spending some time registering with companies to look for it. Registering with companies is an investment in the small business that we are running. Most other small business owners would not make public a list of their clients.