I think I have a gist of what it is, I've just never experienced before.
I'm not ashamed to admit my almost total lack of knowledge about he subject. I grew up in a small town in Nebraska and currently live in a small town in Alaska, it seems that this is mostly a city born occurance. If not a relatively "new" fad.
From what I gather, its people who like things other people don't like so they seem like they stand out. Like growing an unconventional mustache for irony's purpose.
Beyond that, I haven't a clue. Is there anything more to it?