Say "Mattress" 10 times fast

Every where I go, I see a billion mattress stores. I see 10 mattress commercials in a half hour television show. I hear catchy mattress jingles on the radio.
Mattress Firm, Mattress Giant, Mattress One, Sleep Number, Temperpedic...and that doesn't even count department stores and furniture stores that devote entire departments to the sales of mattresses.

Of course there are other things that I'm used to seeing en masse; fast food restaurants, gas stations, drug stores, but these stores all sale things that we buy on a fairly regular basis.

How often do people buy mattresses?

Of all of the people that I know closely enough to have intimate knowledge of their mattresses, I can say with some certainty that my parents were the last people I know to buy brand new mattresses...and that was five years ago. In fact, its common place, at least among the people I know, for them to have 10 to 20 year old mattresses. I think that's disgusting, and terribly uncomfortable but not everyone is as much of a princess as I am. I can also say with confidence that people will go out of their way to not buy a mattress. For instance, my dad who has been sleeping on an inflatable bed for the past year and a half (I know, this seems terribly contradictory to the fact that my parents have a nice, newish bed but I've never explained how my dad works in Memphis and flies home to Tampa every weekend - hence, the inflata-bed)

Seriously. Can you think of anything one might buy less often than a mattress? A car maybe? A house? Even those are debatable.

How do mattress stores sustain themselves? In Tampa alone there are 25 Mattress Firms. If you combined all of the stores in all of the city that sell mattresses, 25 seems like too many. 25 stores of just one of the chains? What am I missing here?

Who is buying all of these damn mattresses?!?!