Why should I blog?

The title could be better, but I need to start somewhere. Apparently, blogging can be done any number of reasons with a variety of styles. I've seen those used as marketing tools and others used as personal diaries. While I often read blogs I really enjoyed, I never thought of myself as a potential "blogger." However, it's becoming more and more apparent that a writer or aspiring writer needs a web presence to succeed. While a home page will be in my future, a blog is not a bad place to start. So here I am. Have I sold my soul? Blogging for money? Perhaps, but if I make a bit of money doing this, I may be able to buy it back eventually, right? We'll see what happens.