Here is a posts that I did with the WP gallery feature. You can see that by making a post with 3 pics/thumbs it actually gave me 4 pages to advertise.
You can put your usual ad at the bottom of the post then you can put html code in the description of the pics thru the media library. Make sure you name you pictures descriptively cuz thats what WP uses to name the fullsize picture pages. Hope this helps