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.
And even if the ads don't shift based on which people are watching, the technology's ability to determine the viewers' demographics is golden for advertisers who want to know how effectively they're reaching their target audience.
