Paco Underhill is the founder of Envirosell, a trailblazer in observational research.
Because of sensitivities surrounding privacy, some retailers are reluctant to discuss surveillance technology. And exactly how many cameras are tracking shoppers is not known, partly because cameras are installed and uninstalled during various studies. (The videotape is for internal use only).
But industry professionals said interest in analyzing shoppers was growing. Video analysis companies said nearly every major chain was or had been a client, including giants like Wal-Mart Stores and Best Buy Company Incorporated”.
more: http://www.nytimes.com/2010/03/20/business/20surveillance.html