Measuring performance by ad size

Is anyone measuring their performacne by ad size? This could give us some insights on how to position ads on our sites

 

you can read an article here

Adsense placement and ad-size tricks to improve your earning

Placement and size of ad can double your ad impressions and earnings.

 

Thanks for the tip, but I was looking for some way to measure how different ad sizes perform.

 

I thinks it depends a lot on design of your site, you can't just check how different sizes perform on other sites and then use the best performing one on your site