Cleverly, the bulb only works when your reading device is actually on and does not work when it is in screensaver mode. (hubpages.com)
This means that when you download a file, leave the machine to go into screensaver mode or are on the front page you'll see an advertisement. (ereaderspotlight.com)
Impress your pals with screensaver mode (full version only). (gamergeddon.com)