Stowe Boyd saith:
It's not a blog without comments, it's not social media without dialog.
Stowe, I think you're wrong about the comments part. This here is a blog and has been online since November 2000, but I didn't host people's comments then and I don't now. I welcome dialog via your blog, IM, email, phone, postal mail, or face-to-face at the conferences I attend. But I don't think dialog requires me to be a hosting service for your comments.