The title is a little over the top, but I have to confess I've surrender completely to Last.fm and I'm addicted to the "internet radio" concept you offer. I've tried several times to explain to some friends what is is and how it works, but it's quite hard to clearly show what really excites me. The truth is that most people don't get it and never will because they're too used to illegal music sharing and downloads and they can't find here nothing that they can't "get" somewhere else, and they don't feel a guilty conscience.
I'm no saint, but I like how it feels to hear music legally, not for any fear or any sort of respect for the record companies, but because it seems a more likely way to resepct the author's wishes, and those are the only that interest me.
And here, at Last.fm I can listen to everything, as I do in a radio station, but not being allowed to download all music (according to the label's and artist's wishes), makes me feel comfortable, as an artist myself (even if most of my work is available as a free download).
It's the closest to real radio as it gets (in terms of copyright), without its disadvantages— commercials and other interruptions, and the whims of the DJs— and several advantages: being able to shape my own programs by tags and artist's similarity or by recommendations and the general taste of the community (my least favored option), being able to check more information about what I'm listening to (or what I was listening to a while ago), having a database kept by an active community in a very effective wiki system..
But Last.fm is more than a valuable "upgrade" to the concept of radio. Its surprisingly vast library offers seemingly neverending hours of music that suits my taste, some of which I didn't knew existed, in several genres that have no (or little) space in conventional radio (and I'm not referring to my, João Martins, music).
Try to ask Last.fm for artists similar artists to Fred Frith, Derek Bailey, John Zorn… or Charlie Parker, Ornette Coleman, or Igor Stravinsky, György Ligeti, John Cage, Jean-Claude Risset, or… Black Sabbath… you got the point or do I have to suggest Nelly Furtado for you to build your own commercial radio? ;)
If you really try it out, you'll notice that the most extraordinary thing is how the choices flow and how the relations between artists are built either by suggestion from the label or artist and by tracking and analyzing the community's listening habits. It's almost certain that not only you'll hear the music you're expecting and wanted to hear, but you'll also hear music you didn't knew you wanted to hear, music you had forgotten, music you'd never thought about placing in that same "shelve", music that's truly new... it's a world of possibilities.
Or am I really lucky? Is it just me?
As a self-centered joke I'll admit that on of the "stations" I've benn tuning a lot is "artists similar to João Martins". And even then I get surprised! ;)