Like the great magazines of yesteryear, Boing Boing lets really smart people tell us about the things they find interesting. When Boing Boing went from 'zine to blog, it was able to amass a huge audience with anything-but-mainstream material, as did many other sites that aggressively stuck to their own voices and their own interests in the early golden age of online writing.
That was the appeal of the Web to me from the start-that what seemed too niche for the "mainstream" could flourish because you had a mechanism (search, links) for reaching all the oddballs on your frequency. To paraphrase (and reverse) William Gibson, your readers are already here, they're just evenly distributed. The Web brings your true fans together. I call it gerrynerdering.