Tracking Shoppers In-Store? Easy. Figuring Out The Best Way To Track? Much Less So

As retailers have been stressing themselves with questions about tracking customer movements—Should we? How far should we go? Who can we trust to help us? Will the data leak? Why didn't I listen to my mother and go to medical school?—vendors have been getting creative about every conceivable way to perform that tracking. Earth's gravitational pull? Sending invisible signals from lightbulbs? Piggybacking over audio waves from existing sound speakers? FierceRetail has compiled some of the more creative ways to track in-store shoppers. Slideshow