[Stormcaller]

Well the data sent is "window.innerHeight" so if 1920x1080 is a popular screen resolution, some people will be using windows XP which will have 30 px taskbar size, and some people will be using 40 px taskbars with windows 7. Then some people will have browsers "not maximized" so they will be missing a few pixels too, and so on.

So from single height value, we have many variations differing by few pixels. Then, I think, we can gather some popularity info from this, if there is many variation around 1080 and less around 1200, this would mean the former is more popular.

So we don't need devices with different sizes but just a few different software choices.

or so I think.