this is the best analysis of what a blog is and what it does and how it works that i have read:
Why I Blog by Andrew Sullivan
NOVEMBER 2008- ATLANTIC magazine

the key to understanding a blog is to realize that it’s a broadcast, not a publication. If it stops moving, it dies. If it stops paddling, it sinks.

But the superficiality masked considerable depth—greater depth, from one perspective, than the traditional media could offer. The reason was a single technological innovation: the hyperlink… a blogger’s chosen pull quote, unlike a columnist’s, can be effortlessly checked against the original. Now this innovation, pre-dating blogs but popularized by them, is increasingly central to mainstream journalism.

The blogger can get away with less and afford fewer pretensions of authority. He is—more than any writer of the past—a node among other nodes, connected but unfinished without the links and the comments and the track-backs that make the blogosphere, at its best, a conversation, rather than a production.

a blogger is… similar… to the host of a dinner party. He can provoke discussion or take a position, even passionately, but he also must create an atmosphere in which others want to participate.

You can’t have blogger’s block. You have to express yourself now,

People have a voice for radio and a face for television. For blogging, they have a sensibility"