He’s spent the past three years developing new camera software that scans facial expressions to identify fan behaviors — think cheering, jeering, talking on a cell phone — in real time at a stadium. So a company can measure, for example, how many eyeballs are attached to a Jumbotron ad (are fans looking?) and how well it’s being received (are they laughing? Smiling? Fiddling on their phones and ignoring it?).