They come in a variety of flavors but the basic idea is that you go in, usually on a real estate shop of some type, to talk with a salesperson. You are wired with a small video camera and are responsible for making sure that the agent you are talking with is on camera the majority of the time. Pay on these is usually better than with the normal mystery shop. Here is why I have avoided them:
1) The equipment is usually sent to you and you are responsible for its receipt, set up, use, repackaging and return. That is not too bad if you get a piece of equipment in good working order. I believe they pay shipping both ways. Any problems with the equipment are presumed to be your problems.
2) The shops are usually "target" shops where you are to interact with a specific person. You may be given their work schedule or you may need to call them and set up an appointment. Many shoppers have learned that these shops are performed often enough that their "target" sees them coming and will deliberately not be present at an appointment time. This means that many repeat visits may be necessary.
3) If you are setting up an appointment you are generally required to give good contact information so that the "target" can contact you to change the appointment if necessary. Several shoppers have had annoying follow up phone calls about whether they have decided yet to take the unit or not. Even worse is several shoppers have had ugly phone calls from "targets" who performed poorly and blame their problems on the shopper--and they have the shopper's phone number because it is not difficult to figure out who you showed a 2BR apartment to on Thursday afternoon last week when the shop was done.
4) Then there are the MSPs themselves that do these shops. Many shoppers have had difficulty with EPMS when they asked for suggestions on how the situation they are facing should be handled. "Just do it" is not helpful, especially when you are subsequently penalized on your pay because you were not able to get whatever information was that you called them about because you were having problems. My understanding is that Video Eyes is much more helpful in helping you with shop snags.
Guess that was more than you wanted to know
Perhaps some folks who have successfully performed these shops can give an up side because it is a shop I won't touch because of the down side.