I use this as a way to add some side income and lower our restaurant budget as well, this month I'm at $145 in "fees" and $275 in "reimbursements". Most were places or things I would do anyway and I get paid to do them - gas stations, an oil change, grocery store, date night dinner at nice steakhouse, shipping something at the post office, a couple fast food for my teen daughter and the one I love, but would never pay for on my own - getting my car washed and detailed. I'm pretty picky and there is still a lot for me to choose from, but the reports can be tedious and do take time, you always need to make sure that you are not working for nothing.
I didn't pay a dime to get my car taken care of last year - oil changes, emission test for license plates, brakes checked, tire rotation, new windshield wipers plus lots of free gas. Other great freebies from last year were movie tickets, science center tickets, clothes for my teen, jewelry, hair cuts, wine, makeup and plenty of restaurant meals.
It is amazing to me the things that are shopped, I noticed lots of timeshare places give you seven free nights plus a $100 fee and a bit of travel expenses to go record a timeshare presentation. I've also seen hotel rooms, amusement parks, golf, massage places and lots more. I often wish I could find somewhere to shop getting a pedicure, that would be awesome.
This site has a list of all the companies (
http://www.volition.com/mystery.html) and if someone asks you to pay them to shop, it's a scam. Marketforce is a great one to learn, their reports are easy. When I try out a new company I'll do one shop and make sure I get paid before I do another, you can also google companies to make sure they are reputable.