What do you call a person who leaves a comment on your blog?

Well, if they've left you a comment, you could probably safely assume that they are also reading your blog, so I guess you could call them a reader? A reader who left a comment? :) This is a pretty tricky one, but the fact that "blogger" has pretty much become a noun describing one who blogs, "commenter" or "commentor" may eventually come into regular usage as well. (As an aside, when I typed the first spelling into Firefox, it tells me that commenter is a word...)

I call them "terribly cool!" ;-) And, as a writer. the language evolves. Call them a commentor and see if it catches on.

I would call them reader as they read and leave comments on my entries. Comments are valuable as it helps to create interaction between the author and readers. I normally try to reply to the comments posted.

There was a mini-debate once on a blog I read about the word "commenter" and one blogger who insisted they are "commentators". I don't really think commentators is right as they are not being interactive, as blog readers are when they leave a comment. I don't see anything wrong with using commenter as there are still spell checks that don't recognize the word "blog". The language changes with the times and there are always new words being added as technology moves along. Check your Websters from a few decades ago and there are lots of words you won't find there but that are commonly accepted today or newly coined to fit the needs of society and science.

I call them loyal visitors :P