Banner Add for Blog Explosion

I've been playing around with Blog Explosion in order to get some visitors to my Blogs. Basically, for every few blogs you visit, someone visits your blog. It gets more complicated than that, but if you build up credits you can use them to have a banner ad placed on their site while people are browsing the blogs. So, I decided I needed a banner ad and found this site AdDesigner.com to make free banner ads.