Can someone explain to me the point Krugman's trying to make here? Right now I think I agree more with the first few commenters.
it's simply microeconomic musings about google's monopoly on synchronized feed reading, which is important to a lot of people but not very important to others, and not very profitable overall. he makes a comparison to public services. he doesn't really have a point, he's just describing the situation and speculating about possible future ways of handling infrastructure like reader.
Google didn't have a true monopoly on feeds, though, that's ridiculous and I would expect a guy like Krugman not to bother making that point. There aren't really any barriers to entry in the field, there are tons of alternatives; it's all about name recognition. EDIT: and I don't think the whole fixed costs thing really applied either.