Should Blogs Have Comments?

Should blogs have comments?

It is a question that comes up fairly regularly in blogging circles and one that different bloggers take different approaches to.

Most bloggers have them - they’re on by default when they set their blog up and they never switch them off. They see the comments as adding a lot to the blog - making it a place of shared learning, interactivity and dynamic conversation.
Other bloggers decide not to have them. Their reasons vary from not having time to moderate them to being frustrated by comment spam.

Between these views other bloggers take a variety of other approaches ranging from:

having comments on some posts but not others
switching comments off over a certain amount of time (to protect from comment spam)
to not having comments in the early days of a blog and switching them on later once there is a big enough audience to justify them (this is what I did on DPS).
to requiring membership for comments (thereby effectively switching them off to the general public and reserving the privilege to comment for those willing to sign up).

There are many options - but I thought it’d be interesting to open it up for some discussion.