There are all kinds of civics-class answers to that question. But how true are they? Could it be that we like to read about war, politics, and miscellaneous heartbreak simply because it's (gasp) entertaining?

You've seen them — everywhere! — and often clustered together, as if central planners across America decided that what every city really needs is a Mattress District. There are now dozens of online rivals too. Why are there so many stores selling something we buy so rarely?