Can I do a "digital-only" release if I don't have CDs to sell?

Yes. If you do not have any physical product or plans to make any, you can still sign up with CD Baby to sell your music digitally. 

Here’s exactly how to do a "digital-only" release:

• Sign it up at CD Baby like any other album.
• Pay the setup cost including the barcode fee if you don't already have one.
• Use the uploader in your member account to provide us with artwork and audio OR burn one finished, mastered copy of your music onto a regular audio CD-R. (NO mp3, aiff, or wav. Just regular audio CD.)
  • If you burn a disc, mail that one CD to us with a note explaining that it is for digital distribution only. IMPORTANT NOTE: Please do NOT send us one of the master copies of your CD (that you’d get back from your mastering engineer), as we do not send the CDs back, except upon request, and it will likely be recycled after 6 months.
• We digitize it and distribute it to all of the usual digital distribution outlets.
• Voila! There's your digital-only release.

You can check out the following section Submission Process - General, for additional information.