Best Adsense Formats
No real surprises, but an official confirmation of what the three top performing ad unit sizes are, something that AdSense has not said publicly before.
So to recap, the top three are:
* 336x280 large rectangle (four ads)
* 300x250 medium rectangle (four ads)
* 160x600 wide skyscraper (five ads)
There has been lots of speculation about the best performing AdSense ad unit sizes, and the 336x280 has always been the best ad unit size in my own personal experience. But even the best performing ad unit size will not perform well on a site if it does not suit the page layout.