Had anybody else tried being a mystery shopper?

A month ago, I sent an online application for a mystery shopping job. A few weeks later, I was assigned to survey a store (without the need to buy anything from it) and submit a report after the task. The project coordinator and I discussed on the phone how I should go about the whole thing. Prior to the instructions though was a question from her that went "Do you know what it means to be a mystery shopper?". That was quite simple, and I guess she was convinced that I know what she's talking about. After the conversation, she sent me a set of questions that would be my guide for the task.

So I went to the store, studying carefully the entirety of the place--from the greeting of the staff when I entered the shop to product presentation, to the maintenance of the store, and to how the staff delivered during and after the transaction.

I'm expecting to be paid this week. The pay is very little, but at least I didn't have to spend a cent. It was overall a nice experience.