A primer on how the smartphone generation is redefining communication.

Haley downloaded the app for fun. Now millions of people watch her videos.

Inside a world where a user named Pizza can amass millions of followers, transform internet humor, get caught peddling diet pills in get-rich-quick schemes, and have her blog shut down—all before graduating high school.

“She scrolls, she waits. For that little notification box to appear.”

Hanging out with a new celebrity class: the teen kings and queens of social media.