Ads that watch you

Its been written in numerous science fiction. Like most good science fiction; it comes true eventually. Those videos ads that have been popping up in shopping mails and airports around the world have more than meets the eye. From SlashDot:

Small cameras can now be embedded in the screen or hidden around it, tracking who looks at the screen and for how long. The makers of the tracking systems say the software can determine the viewer's gender, approximate age range and, in some cases, ethnicity -- and can change the ads accordingly. That could mean razor ads for men, cosmetics ads for women and video-game ads for teens.