Today Google have released another Labs product called “Browsersize”. What Browsersize does is gives you an overlay on your site which shows what percentage of visitors can see areas of your page.
The idea is that screen resolution isn’t the only factor which determines the viewable area – as the browser window could be smaller than other windows.
Research from Google has provided the data to produce this overlay which shows what your visitors are going to see.
They give Google Earth as an example of a site where moving a button up by 100 pixels reached a far greater audience and resulted in a 10% increase in conversions!