It's extremely popular, with readership in five figures, and typically more than a hundred daily comments on various posts. One of the best things about it is that it has many readers who are smarter than me, and/or more knowledgeable than me on just about any given topic I'm interested in. I've made a few really good friends and a lot of friendly acquaintances through the blog, all over the world.
Maybe my case is a rare exception; that wouldn't surprise me. I've tried, for example, to write the same kind of eclectic random-thoughts blog in English -- my primary blog is in Russian -- for a few years, and never got more than 100-200 readers. Maybe I wasn't giving it enough attention (it's semi-dormant now, though I'm trying to find tuits to revive it), or maybe in English, a non-specialized blog has a harder time attracting attention. Or maybe much of it is random. Among the blogs I read (40+ in English, a few hundreds in Russian), most widely-read ones are either by famous people or specialized to some topic; but there are some exceptions like me.