Flood YouTube with live performance clips, interviews, and videos (if they have the means). Tweet at least once a day, not necessarily about the music, but with what your friend is up to, funny observations, etc. People don't buy music, they buy personal connection/image. Tweets with pictures get retweeted twice as often.
One reason you want a lot on YouTube, if you're clever about it, is search. When you upload videos, include as many relevant tags as you can. They work the way Keywords worked on Google 15 years ago, and are ranked when searching by the popularity of the video. If you build a nice Twitter following, it's easy to... "popularize" a video. We won't say "manipulate." That would be wrong....
So, you can see where I'm heading with this. If you knew how to get easy Google rankings via SEO in the late 90's/early 00's, you can get good organic search traffic on Youtube now.
Be sure to monetize every video and include links to iTunes or wherever your friend is selling the music. (Spotify is big in Europe, but still hasn't really gotten huge in the U.S. ...Do it anyway.) You'll probably make more income from your YouTube/Google ads than from selling the music via the links, but so what?
Be sure to have all your copyright ownership paperwork (or license documentation from Harry Fox Agency if they do covers) BEFORE uploading and monetizing the videos. YouTube is very strict about copyright, and although they'll still place the ad on the video, if you don't follow their document upload process precisely, you won't get the money - the copyright owner will.
Also,
Discover and Buy Indie Music CDs, MP3s. FLAC, and Vinyl | CD Baby Music Store is the go-to, one stop shop for organizing self-released music. Excellent resource, but be prepared for a lot of work.
