Huh. cool. Of course, even if that problem is solved, it's still very difficult to track meatspace interactions (I spend, actually, more money on meatspace ads than on online ads. check out the checkout lanes in the safeway on shoreline in mountain view.)

If I'm right that people are willing to pay more for advertising they can track, and that meatspace advertising will remain nearly impossible to track, meatspace advertising will remain undervalued.