<snip> have a look on this page i also use adsense in the footer just open your root folder and go to wp-content then themes and after that choose whatever theme you want and after that just edit footer.php and add your ad sense code in the upper of all codes simple done.
Even if it were that tall, the ad would not go to the bottom by itself. I knew you wouldn’t like the gap at the bottom, but it was the only reliable way I could think of.
As long as the right column is always to the right of the ad then the negative margin will work fine as the right column will just get pulled into the extra padding that was added.