for the sake of studying the usability of an interface (such as a website), people use heatmaps as a way of tracking the click rate per screen area.

i like it because it’s a dead-end example of why words like “virtual” do not have any sense: it underlines the materiality of a visitor’s presence on a website.

http://www.etre.com/blog/2006/05/five_days_dixonscouk/

heatmap