There are ad spaces in the content of the first and last post, but not after those elements. If that works for you, you can add advertisements there by creating a new Banner Space for each of those advertisement areas.
Well, those spaces won't work. I already tried that and it ruins my posting formats by pushing everything down and messing up the alignment. I might be able to make them work if I knew how to make them float like I do the pictures in my posts.