I'm sorry for OT, but the kano.me link does a strange thing I notice lots of websites started doing recently. The moment you move your mouse to close the window it creates a popup. Why, and how? I feel really naive asking this but do websites now track the pointer position?
It's likely a "mouseout" event to detect when the mouse has left the window. Though I haven't checked the source to verify, so take with a grain of salt.
In Chrome you can find it out by searching for 'exit-intent' event and setting a breakpoint on that. They use the mouseleave event on an element that covers the whole page. When your mouse leaves the web page viewport it will trigger that.
