Not just a problem for Detroit, any longer
The mattresses are sent out to Mattress Farms and run through a washing plant, re-covered, re-wrapped and sold back to the stores at a discount price. Now if your being told that upfront and that is your choice to purchase it then I say no problem, but watch for bed bugs, mold, pet stains, urine etc.
On the other hand what if the store makes you feel like your buying a new mattress straight from the factory and not telling you they have been used. Now that's a problem and buyers are the ones being taken to the cleaners.
You will be able to tell if it's a possible refurbished mattress by the law tag, if it has been removed, or take notice of the offer if it's too good to be true, if the salesman is evasive. Most commonly on The Top Names like Tempur-pedic, Sealy, Serta and Stearns & Foster. The manufactures have the strict policy to tell the dealers what the national minimum is that they can sell their products for and if they break that rule and sell it below the national minimum pricing, called map pricing, then they loose their dealership with that company. It's the law for the big box chain stores...