Many of my clients have been asking me if they should release their music on CD or MP3. In many ways, this is a no-brainer answer for most engineers. Yet, there are advantages to both formats. I'd say it has to ultimately come down to your budget.
CD audio is scientifically a higher resolution, but also comes at a higher cost. MP3 audio is easier to distribute and has the advantage of encoding metadata directly into the file. If you have the budget, go with CD masters, trust me, your fans will appreciate the increased audio quality. MP3 files can always be encoded from the CD audio.
If you do release MP3 files for your music, please use a quality codec and encode the files at 320 Kbps. Audiophiles like myself can hear a noticeable difference in the quality of audio as the Kbps encoding is lowered. A quality codec will also dither and render your audio without adding too many artifacts.
This topic can go on and on, so please leave any comments or questions and I'll respond as soon as I can. Thank you for reading this blog post.