Yep, Returning merchandise has become very popular. Most return policies are so lax, a lot of people don't shop around anymore, they just buy and return if they find something they don't like. A ton of refurbs are just the same as new. I'm sure some items that are more than $100 they actually spend time and refurbish, but I would guess 9 times out of 10, it is just an open box item.
I have also seen refurbished pop up in clearance situations. They might really have some refurbished in the mix, but they will just mark everything as refurbished and clearance everything. That way they don't have to honor returns after 60 days or whatever and can clear their inventory completely. I have gotten some nice new items cheaply that way, still completely sealed in box.