The dark-- or at least gray-- side of blogging includes the fact that most of the Technorati Top 100 blogs are group blogs or professional blogs, usually aimed at marketing in some way. I suppose it makes good business sense to hop on the buzz-mot-du-jour bandwagon, just like Hagel and Armstrong did with Net Gain: Expanding Markets through Virtual Community. Who people link to in their sidebar, their "blogrolls" (which are often labeled "who we read"), is overwhelmingly gendered, in her sample. And the top dogs all get linked to, but don't link anyone.
It's not a solid quantitative research study, but it's interesting to read.