What exactly is Media Mail?

All I know for certain is this: If anyone ever asks if they can send you something by media mail, suggest they just throw your item in the garbage can instead. At least you'll know exactly where it is and isn't.

Two out of three things that I've had sent to me by media mail are lost in time and space. A universal shrug. Jimmy Hoffa is reading my "Cold Comfort Farm" book and listening to my Monty Python Contractual Obligation album right now.