Blog or die?

Blog or die is the actual subhead of a book I am reading called Naked Conversations, How Blogs Are Changing the Way Businesses talk with customers. For me, it has been a crash-course in blogging. I now am exploring how blogging affects work/life balance. Since I began a blog, I have added extra responsibility to my workday.
I've been told, the most successful bloggers invest significant hours of their lives into blogging. I'm guessing there's a cost, a toll on your personal lives. If you have an experience with this, please share the details.