Where this becomes really interesting is when taste cross-pollinates between one medium and another. The guy in the Kraftwerk t-shirt may recommend that I read Douglas Coupland's Microserfs. On the surface, there is no direct connection between Kraftwerk and Douglas Coupland. But underlying both of these signifiers is a whole world of shared cultural assumption and contextualization. Not to mention the unspoken trust implicit in the transaction of ideas, which goes something like this: the guy in the Kraftwerk shirt is obviously an individual of high intellectual quality, because he likes the same things I do. Therefore, his recommendation is likely to be of the same high quality. Nobody thinks this consciously, of course - to do so would be to admit to a certain egotism about one's own intellect and taste. But we all think it nonetheless. This person likes cool stuff, therefore, they must be cool, too. Again, it might be superficial - but it turns out to be correct most of the time.
He goes on to tie this in with the phenomenon of blogs-as-commentary, or as advertisement of one's interests/tastes.
Many people - myself included - use their blog not only as personal diaries, but as a sort of informal critical journal. Surf any random blog and you'll find a few reviews of books, movies, albums, or concerts. Because bloggers are not under the same commercial constraints as mainstream media sources, the length and subject of these reviews tends to be far more diverse - one blogger may write a 2,000 word critical essay about the Clash's London Calling, another might write a 500 word review of the local band they saw last night. I might write twelve different pieces about Bruce Springsteen's Nebraska while drunk, and probably have.
While it might be argued that this tendency to publish one's opinions is somewhat self-indulgent, the same can be said of professional criticism. My personal experience as both a blogger and professional journalist is that the level of quality in the blogosphere is pretty much on par with the mainstream media, which perhaps says more about the mainstream media than anything else.
IMHO, using blogs to kibbitz about electroclash or avant-pop literature (or just about ideas/concepts in general, i.e., whether "electroclash" or "avant-pop literature" are overrated/a load of rubbish or not) is a lot less self-indulgent than using blogs to kvetch about one's (lack of a) girlfriend or expound one's daily routine in excruciating detail. Or, as some Portuguese blogger called it, "masturbating in front of a mirror". But I digress.
It happens because minds think alike - great minds, lesser minds, minds that really love Jean-Luc Godard or Kenneth Cole or the booming garage-rock scene. The Russian lap dancer who links to my ninth drunken review of Nebraska is likely to be someone whose tastes I instinctively get - like the theoretical guy in the Kraftwerk t-shirt I mentioned at the beginning. If she likes Nebraska, she probably likes the Cowboy Junkies. She might read Flannery O'Connor (whose short stories heavily influenced Springsteen when he was recording the album). If she doesn't, I can suggest these media to her. And in return, she can turn me on to some vastly beautiful and eminently depressing Ukrainian alternative country band that I would never, ever have come in contact with otherwise. She is another member of my taste tribe, and we can introduce each other via our links to others like us.
But wait, there's more! This also ties in to the concept of decentralised discovery of good music, and the impending death of the RIAA and extinction of the manufactured Britney-clone armies. (via Die Puny Humans)