Tumblr is a creative outlet where they can anonymously express themselves by posting photos, videos or bits of text on topics that interest them, such as Harry Potter, Ryan Gosling or fashion obsessions such as flatforms. They can connect with people they know and get to know people who share their interests, creating a sense of community without revealing more about themselves than they want.
Megan Peranteau, a senior at Poway High School near San Diego, has deleted her Facebook profile six times, and swears this time it's for good. She has switched to blogging service Tumblr as an outlet for her opinions, photography and art. Now that she's no longer constantly checking status updates, she and her friends have something to talk about when they meet in person.
"It's allowed me to create stronger relationships with people I do hang out with, now that they're not right in my face all the time," said Peranteau, 18.
Teens who belong to the first truly mobile generation — their most common form of communication is text messaging — are increasingly gravitating to services made for their smartphones and tablets like mobile social network Path. Photo-sharing apps are also very popular, especially Instagram. Facebook agreed to buy the mobile app maker last month for $1 billion to keep it out of the clutches of Apple and Twitter, people familiar with the deal said. Another new service, Snapchat, enables iPhone users to take and send a picture to a friend that is visible only for up to 10 seconds.
Parents are nervous about teens swapping Facebook for services that can popularize risky behavior such as "sexting." They also don't like being unable to peek over their teens' shoulders.
But, Marwick says, that's the point.
"And honestly, I believe it's a good thing," she said. "Teens need a place to socialize and express themselves without grown-ups staring at them."
Still, for most teens, Facebook is still tops.
Amanda Lenhart, senior research specialist at the Pew Internet & American Life Project, said Facebook has seeped into every nook and cranny of teen life.
"Facebook has been remarkable in its ability to saturate," Lenhart said. "The only thing that comes close is the land-line telephone."
Land-lines? Who answers those anymore?