A key thing with this service is that it's FREE for mp3s you buy from Amazon. From their help pages -

"All new Amazon MP3 purchases saved to Cloud Drive do not count against your storage quota."

So, if I buy mp3 files from Amazon, I have a free backup AND and I can play them across any Internet connection or from an Android phone. This puts Amazon's online music store on a more competitive footing against Apple. To date, Apple's advantage has been its integration of Store + Music Management + Portable Playback. For the growing number of Android owners, Amazon's store offers a comparable level of integration. I may even draw some iPod/iTunes users to Amazon.

Actually, decent sewer systems are a lot more recent that that. Romans only had sewer systems in large cities. European royalty still died of cholera in the 19th century and the US had a cholera epidemic as late as 1910. So effective modern water treatment and sewerage has only been around since the early 20th century.

First hand, I own a 19th house in a medium sized city on the US east coast. Built on the edge of town in 1855, it had an outhouse until the early 1920s.

There are many fields where major lapses in professional ethics will kick you out of the profession for life.

A fiend of mine who's a cop once busted a guy driving a dump truck while under the influence. Not only did he have the DUI on his regular driving record, the conviction cost him his commercial driver's license PERMANENTLY. He can never drive any truck for a living ever again. It may sound harsh, but the driver was swerving while driving a vehicle that could level a house.

Likewise, there are criminal and even just negligent behavior that can cause lawyers, accountants and doctors to lose their license - flushing away years of experience and education.