I did one a few weeks back and like others have said, finding the backstock was a bit of a challenge. When I found it, it was 15 boxes. The boxes were mostly women's slippers which were pretty well stocked on the display, so I had to go through multiple boxes to find gloves and men's slippers, then haul it over to the display (you can use a cart for this or the boxes are fairly light). After redoing the display, I put the boxes where the store had an area that looked like they use for breaking down boxes, as there weren't any employees around and this was in the back section of the store. None of this was really spelled out in the guidelines as to what to do with the boxes, so I just tried to do what seemed logical. It wound up being about an hour of work, maybe less. The one I did had a decent bonus on it.
I don't know if they are aware of the real effort behind some of these when they are putting them at $12, especially if they want quality work to be done.