There's a lot of discussion around the Web about whether blogging is good for writers, or whether it's another time-sink.
I love this insight from Alison Kent:
My response? You're not writing in your novel if you're posting messages about blogging to a Yahoo Groups list! Might as well BE blogging. It's great therapy. It keeps you in touch with authors walking in your same shoes. It loosens your writing muscles. It's often times as valuable as attending a writing workshop. Or a marketing workshop. Blogging is an idea generator, a mental exercise program, and a hell of a lot cheaper than a psychiatrist!