Earlier quoted context omitted.
I have also purchased music on Amazon and let's not pretend its "full on downloads", Amazon has V0 MP3 only iirc and Bandcamp offers ever format under the sun including FLAC and ALAC. Don't know about Apple because iTunes doesn't have Linux support and the whole setup of downloading an app in order to download a file strikes me as a bit gross.
It's true Amazon doesn't offer lossless audio downloads, but they're very good quality, and DRM-Free. iTunes downloads are AAC, 250+ kb/s (remember this bitrate is with a more efficient codec). I'm probably opening a can of worms here, but I'm really quite skeptical more than one in a million people could tell the difference between iTunes and lossless in a blind test. Maybe drop that to one in a thousand for Amazon…
I only buy music on itunes as a last resort, so I don't have a huge sample size.