Digital music began its life as a pay-per-song enterprise that, over time, has become dominated by the streamers like Spotify, which let you enjoy unlimited access for a flat monthly fee. Amazon, which has been selling eBooks one-by-one to bookworms for quite a while, has finally switched to a more contemporary system in line with what consumers expect of digital content services, and those tethered to the new $9.99 subscription package will be able to read all the books they can handle for the same fixed rate per month.
