This is a nice little example of a popup that appears when the visitor moves his cursor from the page to the top, in order to close the browser window or navigate away. While this is not a TRUE exit popup in that it won’t arrest the browser, preventing the browsing or closing action, it nevertheless has a striking effect and may well make the visitor think twice about leaving.
Go ahead, make our day… try it out for yourself by moving your cursor off the page to the top. 
To close the popup, simply click anywhere on the page (away from the popup) or wait 15 seconds.