By default, my blog has commenting disabled. Initially, this was done for two reasons: to avoid blog spam, and to prevent my friends from posting inappropriate messages, as friends tend to do.

There is also the philosophy that having a blog with comments enabled - but no comments - is a sign of a bad blog, and may cause you to actually lose readers as a result. This is a common problem in "social medias" like forums, social networks, etc... - they are basically classified as uncool until that tipping point of popularity is reached, and strangers feel comfortable to jump in. Here's a hint: If you're launching a forum/blog/etc... , fill in a whole bunch of threads/comments yourself - at least one page worth. Make sure to "beat the path", making it easier for strangers to trust it.

I also find myself judging the quality of blogs sometimes by the quality of its comments - no comments means you can only judge the quality of the blog based on the writings.

Anyways, I've rambled enough. Feel free to comment :)