I think blogging is inherently hard because there is a different expectation than Facebook or Twitter. The medium, and our eexperienceswith it (reading popular blogs for example) make it that we believe this is somehow more formal, that it has more staying power. Part of it (for facebook at least) may be the lack of the public being able to view your writing. We therefore want to polish it. We don’t want to write something that is not air tight. It’s easy to post a random thought that is not worked out to Facebook, but on your website? It feels like the bar is higher.