How do mattress stores stay in business.?

I can think of at least half a dozen mattress stores in prime locations (high end strip malls, small buildings in upscale and high traffic areas, etc). I don't think I have ever seen any customers in them. I know these places are leased for thousands of dollars a month. With the employee costs, utilities, taxes and everything else, the overhead on running a store there must be close to 5 figures a month. I, personally, have bought 3 mattresses in the last decade (all of which have a 20-25 year warranty and none of which were more than $400). I ume that is fairly normal. So, how on earth can these places afford to stay in business? Any ideas?