With your excellent post below on the MyDD article, what's left for me to add?
Well, doesn't "market" imply some kind of money changing hands? I haven't seen any. Why, just this week in the heat of battle on a thread at one of the big name blogs you mentioned, I said that if I was wrong on a major point that I'd give every cent I'd made blogging to the RNC. It was an offer much easier to make than the other side seemed to realize but they had no homepage listed.
I've always figured most blogging as volunteer work, either by choice or by default.