Nick Carr's blog turns forty-eight (in blog years) and he offers up a great post explaining why blogs can be Parasites, scavengers, commensals:
"What I'm getting at here is that blogs need not be narrowly categorized as parasites or scavengers. A blog, like the larvae of a humpbacked fly in a termite colony, can be a scavenger or a parasite - or even, for that matter, a commensal. Or all three at once."
The Google Ads about intestinal parasite medication and food testing are the icing on the cake ;-)