I like phone and computer shops since they seem to be easy and sometimes you can build a route of just these shops. Of the last 8 that I did, 7 were at the same address that I had conducted shops previously. I figured that the odds should be low that I would come across the same salespeople at each shop -- wrong!
7 of them were with the same CSR as before. Most seemed to remember me from my last visit. One location I went to was a new one for me that was an hour away and figured no way will I get the same CSR. It wasn't until I was wrapping up the shop that it dawned on me that I had spoken to this person at another Best Buy closer to my house.
How long do you typically wait before repeating these types of mystery shops at the same address? I saw a few pop up in my area that were mostly of sites I haven't visited before, but they were scooped up before I could get them.
Retail oil mystery shops are different in my mind since you are making a purchase and you aren't asking questions about watches and buds or tablets.