>>> Writing blog posts about running startups - This feels good. If it gets onto Hacker News and gets a lot of views, you'll feel really flattered and proud. But don't confuse people reading your post with people knowing and caring about your company.

Not sure I agree with this one.

I've worked at two startups and both made major inroads in industries they wanted to break into by doing this. They wrote several posts that were published in various magazines and "{trade rags" for their industry.

It gave them exposure and explained what their application did and how it could solve an industry wide problem. Doing this actually landed both companies a major corporate client.

Blogging about general stuff isn't work, and if you're trying to get it on HN or some other "technical" site that is not related to your business, then yes, not work. If, however, you get it published in an industry specific newsletter, magazine or trade paper, I would say it will worth it.