but does anyone know whether the link opens in a new window once clicked or uses the same window as your webiste?
It opens in the same window . If it opens in another window then the ad code might have been modified and that is against TOS !
it opens in the same win. don't click on ur ad code but u can try in which frame link will open by leaving some clicks to other publisher site. (opening ad in a new win means ad code is modify which is against the TOS, coz adsense pays if u send ur visitor to the advertiser site.)
It's open on the same window, There are some tricks to open AdSense in a new window. All this tricks are against the Google AdSense TOS, and you could be banned if try them. Some tricks use DIVs and are there on the gray area. In my opinion just don't do it.