Vera Wang has mattresses

What I don't understand about this is why? I mean I kind of get why she would design other things then women's clothing--like stemware or something--but mattresses? Does a mattress need a designer? I understand an engineer to make it super soft or sturdy or firm in just the right way, but why a designer? Does it really matter if the fabric it is wrapped in is designer? Wouldn't you think that people who could afford 'designer' mattresses could also afford fancy (or even non-fancy) designer sheets to swath them in. Doesn't everyone puts sheets on their mattresses at which point there is no way to tell if the mattress is designer, generic, or even creepy and bloodstained. Why a Vera Wang mattress? Why?