The teenage life, streamed live and for profit

ON a recent afternoon in Los Angeles, 15-year-old Bryce Xavier went to the Olive Garden with his mom, pulled out his phone and broadcast lunch. Across the country, teenagers' phones lit up with a push notification: Bryce was live.

The phone framed Bryce in close-up. His mom sat off-camera across the table; her son had really come to eat with his fans. Tens of thousands of them poured into a virtual chat room that layered over his image. A bright stream of emoji floated up the side of Bryce's face, the product of hundreds of fingers tapping the "like" button at the same time.

Bryce is a star on Live.ly, a year-old live-streaming platform with a core audience of teenage girls. Within three months of its release, according to the mobile app data firm SurveyMonkey Intelligence, Live.ly had unseated Periscope as the iPhone's top live-streaming app.