The old, low-tech way of judging consumers’ interest in products was to put them in a focus group and ask them questions. However, some studies on the focus group method have uncovered a rather inconvenient fact: focus group participants often try to please the testers by saying what they think the testers want to hear. So how do you measure interest without asking for opinions? Some companies are relying on three-dimensional computer simulations of virtual stores full of virtual products, then tracking where consumers’ eyes are drawn.

Using special computer hardware and software that tracks a virtual shopper’s gaze, companies can create a sort of heat map indicating where the eyes were drawn and how long the gaze was held at each point. Some systems even use devices that measure involuntary facial expressions to gauge true emotional response to whatever the subject is looking at. The result of all of this technology is that companies are able to test out different packaging, logos, product placement and other important aspects of retail without wasting millions on prototypes and ineffectual focus groups.