I guess I can't answer that unless I know what your goals are... why do you come online, why do you post, what do you want from life. Business goals will be different from personal goals etc It's an interesting discussion though...
For me, the best advantage I get in blogging is that it develops my creativity and forces me to think out of the box if I want to differentiate my blog from the gazillion of blogs out there in the blogosphere. As a corollary, blogging has helped develop my writing skills since content is still king when it comes to attracting readers.
The main purpose of my blog is to keep my past, current and potential clients aprised of the latest news and trends in my field. I am already getting "thank you" emails from them and the blog is only three months old! Of course, I did email the URL to all 1100+ of them about a month ago, so that explains hwo they all know about it. But it sure was a nice pat on the back when I got that first, sincere thank you email! That's why I have one!