As adults, we also crave attention. We want the world to know about something we did, something we know or just to say "hey world, look at me!". Blogging allows for this. It permits you the opportunity to share a story, post an industry tip or promote your new business. Never has there been a tool that makes it this easy to reach so many people at such little to no cost to you.
So the question is, what are you waiting for? If your a business out there looking for an avenue to outflank your competitor in, get blogging. You can't tell me that you don't need to promote your business as it's already too well known. Blogging is the perfect way to let the world about your new "missing tooth" and to get a leg up on your competition.
PS - you can also use blog to promote your own blog and what you have acheived (or not acheived) on your blog! See my post called: Mastercard priceless moment at Anything Goes Marketing