On the other hand (following down-at-the-mouth comments of ye'day), the digital-fidget reality of oure age is indeed a new form of publication. So with these blogs one develops a new form of semi-public literary persona.
The blog impact was more vivid a few years ago, when they first surfaced - in the sub-poetry world, as sort of an alternative to discussion lists. You noticed a creative variety among blogging habits & habitats.
The idea that one can dip around in a blog's archive, since they're searchable (at least to some extent).
But this diary approach is obviously more diffuse than that of the essay. There's more rigor involved in proposing arguments or offering research & evidence in essays or articles.
I can blog in off-stretches at work. But I can't write poetry or compose an essay or a story. To do that requires some solitude & concentration.