Kent Newsome is bang on about Twitter. What I find interesting is that there are a bunch of people who, when faced with a new technology ask only as to it's 'faddishness' and whether anyone's making money. 
What this business magazine perspective fails to take in to account is that fun and creativity are requirements for innovation. Blogging wasn't set up in order to return investment or to get sticky eyeballs (whatever they are).
The point about Twitter is that it's fun and useful.
If one is making money, the intention is that you use it to have fun. Now, if your definition of fun involves snorting cocaine off a hooker's backside, perhaps Twitter (or blogging etc.) won't satisfy your need. But if it involves communicating with one's fellow human beings, then maybe it will.
With the music industry, the people who focus on the dollars and pounds are useful but not the people you want to take advice from on what's interesting. They often drain the excitement out of music in order to pimp boy bands.
This is why I get very bored reading Techmeme - it is often far too high level for me. It's almost TechBusinessMeme, rather than Techmeme. The quarterly revenues or Google AdSense ROI of Silicon Valley startups doesn't interest me - technology does. If we had Musicmeme, we wouldn't be discussing the amount of money that EMI or Sony Music makes, we'd be talking about music, goddamnit!
This is also why I don't go to conferences any more (or rather, why I have my 20 pound/dollar/Euro rule).
