1. Having your own domain name signals a mark of professionalism in the online world. Just as your name is, it gives you a unique identity as you in the internet.
2. And if you are monetizing your blog, it would also give you chances to earn more. Other companies or advertisers prefer blogger’s with own domain name. One of the great “get paid to blog” companies who prefer such bloggers are PayU2blog.com.
3. When your own domain gets a page rank, more opportunities will go your way. Not only in get paid to blog but also direct advertisers.
For me, I got my domain name because of reason #1. I wanted to be different and have my own unique identity online. Then far way later, I found reason #2 and #3 as an added bonus.
Hope this helps!!