In January I started a subscription with eMusic. Thus far I am very satisfied. There are folks who complain (like there are for anything), but many of the complaints I see stem from two sources:
1) Apparently there are folks who don't understand that a service that deals mainly with independants isn't going to have material by Shakira or Metallica or The Beatles or [insert most acts on the big 4 labels here]
2) There seems to be confusion resulting from nobody telling you what to buy
The solutions here are simple. Taking the time to know what you're getting in to before forking over any cash is always a good policy. As for the second, well, the recording industry seems to think you want cookie-cutter winners of televised talent shows on your iPod, so marching down to the local mass marketer (where won't you be confused by a deep selection of options) and demanding the latest as-seen-on-TV thing may be considered your instructions. Somebody's gotta buy this stuff. And if you look at sales figures for American Idol winners after Kelly Clarkson it is obvious somebody's not following directions.
But I'm very happy with eMusic. Here, as much for my benefit in keeping track as for your curiosity, are my March 2008 purchases:
Bikini Kill Pussywhipped
Cat Power eMusic Sessions EP
Dressy Bessy California EP
Gossip Standing in the Way of Control
Gossip The Gossip EP
Heavens To Betsy Calculated
Lucky Soul The Great Unwanted
Ray Wall Band "The X-Men Song"
Sleater-Kinney Dig Me Out
God Damn Doo Wop Band Broken Hearts
Traci Lords "Sunshine" "You Burn Inside of Me"
Portishead "Mourning Air"
Sinead O'Conner "Ode to Billy Joe"
Indelicates America EP
Carter Family "Single Girl, Married Girl"