I've probably said it a thousand times that blogging is a great way to build your "Personal Brand". Expressing your opinion to a vast audience and providing information that they can use right now is priceless. For me, it's a great way to market my expertise.
One key aspect of blogging is to build your audience. It is not enough to just build it, you have to work at getting them to come. One very effective way to accomplish this is to go out into the blogosphere and find blogs within your industry that have built a considerable audience and offer to write content for them.
Once your posts are read, the reader has the opportunity to follow your author links back to your website and/or blog. This is how you reel in traffic and potentially land some new business.