It’s about logging eye tracking on webpages. There’s a movie you can click to. And first of all, it drives me crazy to see that blue ball trashing around on the screen.
But it is interesting to see what a user actually looks at on a webpage/application/product/commercial/whatever.
Take a look at this blog by Greg Edwards for something called heatmaps. It kind of looks like a weather report, basicly you want the important stuff to show up red hot.