Another Super Bowl Ad Fest, This Time on the Cellphone

The Super Bowl remains the biggest mass-market advertising event in the country. But this year, a new kind of advertising -- personalized and based on physical location down to a matter of feet -- will greet fans in Times Square and MetLife Stadium, where the championship game will be played.

At both locations, the National Football League has sprinkled tiny wireless transmitters that can send finely tuned messages to smartphones. It is the boldest test yet for a months-old technology that could change how brands of all sorts market to their customers.