I see certain sites like mashable.com etc have a 728x15 ad format below the title. And they look like normal adsense ads (and not link units). However I don't see any such option in the ad formats presented in my google adsense account.
Do they have special access to those google ad formats or does it work by just changing the leaderboard code and reducing the height from 90 to 15?
Example: http://mashable.com/2008/12/08/how-to-quiet-the-twitter-noise/
I'm referring to the ad, just above the author description .. "Jun Loayza is the Co-Founder and CMO...."