New bed at mattress store? Ok guys, explain new vs. used mattress. I be going to you...

Ok guys, explain new vs. used mattress. I be going to you go into mattress store and they own 50% off if you buy a floor model. However, the floor model is coming from another store so it could be a customer return. Anyway, I get my new (used bed) and it is highly nice and it has the marker showing where they cleaned it as they own to by law. I thought I have done all my research but this is a complete other arena.
Good furniture?
Answers:    It could be a returned mattress from your store. It didn't have to come from another store if you reflect about it.
Where do you live? They cant put on the market used mattresses in my state.