Billboards Looking Back

The basic idea has been tried a number of times. I know of no cases where it is permanently installed. The technology is there but still imperfect. The behavioral data would be useful. See also Videomining. In Slashdot and GoodGearGuide:

... "At a Tokyo railway station above a flat-panel display hawking DVDs and books sits a small camera hooked up to some image processing software. When trials begin in January the camera will scan travelers to see how many of them are taking note of the panel, in part of a technology test being run by NTT Communications. It doesn't seek to identify individuals, but it will attempt to figure out how many of the people standing in front of an advertisement are actually looking at it. A second camera, which wasn't fitted at the station but will be when tests begin next month, will take care of estimating how many people are in front of the ad, whether they are looking at it or not." ... '

Also see this previous post, which describes something similar, not sure it is the same thing. Above picture, a very advanced system from IBM, called BlueEyes, tracks shoppers in a supermarket aisle, painting them in color.