1) Programming matters. Gary Curtis, for FullAudio said that their server stats showed an initial flurry of downloading when a new subscriber signed up, which then petered out after a few weeks. It turns out that having to know what content you want is a drawback of P2P networks. This certainly matches my experience filesharing -- I initially download lots of stuff, but then run out of inspiration.And this is where a reputation system comes in and why record labels are so important. I know that music coming from Warp records is not only going to be of a certain style, but is going to be better than most other music coming from that genre. Knowing that, I will automatically buy or listen to something with the Warp label on it. Chances are that FullAudio, as mentioned above, could benefit from offering suggestions to subscribers based on their purchasing/listening habits. Amazon.com does this in their space.
I listen to a lot of music, to the tune of 6+ hours a day. Almost all of the new music I listen to comes from one reputation database, Usenet. There's a news group dedicated to electronic music (a 10 year obsession now) on Usenet that has an uncommonly GOOD signal to noise ratio. Almost anything mentioned there = me listening to it, and the feed seems limitless, so my consumption continues.
Also worth mentioning as a good place to find good electronic music is Radio@AOL. Who ever is the music director for the Ambient station knows their stuff, and the app always tells you what you are listening too. Consistently good music from the same source builds that source's reputation, but maintaining that is tough. Just turn on the radio and you will hear what I mean.
Do I read music reviews? Not anymore. Zappa said writing about music is like dancing about marshmallows, and while I think that's an idiotic thing to say, it's true. Music reviews always fail to tell me if the music is any good based on my tastes, and everyone is to afraid to say what the music sounds like. Instead, words like 'sublime' and 'mind bendingly' get thrown around like chips at a Craps table (and lost their value just as fast).
I want a music site modeled after epinions.com where tons of categorical meta-data (eg, 'sounds like Boards of Canada') is attached to music releases of all kinds. Those who write good reviews devoid of marshmallow superlatives get rated up and make their recommendations more valuable. Hire some professional and well regarded DJ's to be music directors of their chosen genres and you've got some good rep mojo driving subs and downloads.
You can't just bake a pie and expect it to sell, you gotta let people know it's there and that it tastes good.