Maybe I'm being pedantic, but CDs are higher quality than MP3 usually. You can rip losslessly to WAV or FLAC and preserve the original. MP3 is lossy and will be a lesser version.
Didn't know that. It's a weird disparity that you can't download a PDF when you bought a book. You get an online book viewer instead. I would have expected them to likewise stream the audio if anything, or require you to use their app to listen to it.