A while ago I was asked by my employer to write a short article on something web related to add some decent content to the company's new website. I ended up writing a short article on blogging for business promotion which included a short (and very incomplete) list of what I think are essential elements that must be included to count a website as a blog.
I am sick of stumbling across websites labelled as blogs which are missing one or more elements which I believe are essential to the blog paradigm. This miss-labelling is particularly prevalent within traditional media organisations and other businesses who want to have a blog because it's now the done thing.
Today I found an article by Merlin Mann (via Daring Fireball) which is a much better, and more comprehensive (even if slighlty different) list of what he thinks consitutes a good blog. I can't say (as he suggests I should) that I disagree with any of it but, that doesn't mean this blog meets the mark (or, neccesarily that I'm trying to have it meet the mark).