I'm fairly confident if Amazon was a monopoly they would have been shut down already or at least sued many times.
If proprietary meant monopoly than we'd have many other companies shut down as well and many electronics companies would qualify as monopolies.
Heck, thinking of that AZW argument, isn't an AZW file really just a mobi file with a different extension? It's not even really proprietary. The DRM may be proprietary, but that could be put on top of a plain mobi file anyway.
It makes me wonder (and probably simple enough to check) whether I could rename a AZW with DRM to .mobi and have my Kindle still read it (assuming I'm on the correct device and it is my copy to begin with). Conversely could one rename a .mobi file with a .azw extension and have it work.
Ah well... considering all these Linux distributions and their versions, you'd think the Linux people were a monopoly... Look at all the devices they have their fingers in
