That's been the prediction for a while now, born of numbers showing that fewer than one in 10 teens were using Twitter early on.
But then their parents, grandparents, neighbors, parents' friends and anyone in-between started friending them on Facebook, the social networking site of choice for many – and a curious thing began to happen.
Suddenly, their space wasn't just theirs anymore. So more young people have started shifting to Twitter, almost hiding in plain sight.
"I love twitter, it's the only thing I have to myself ... cause my parents don't have one," Britteny Praznik, a 17-year-old who lives outside Milwaukee, gleefully tweeted recently.
"Facebook is like shouting into a crowd. Twitter is like speaking into a room."
While she still has a Facebook account, she joined Twitter last summer, after more people at her high school did the same. "It just sort of caught on," she says.
Teens tout the ease of use and the ability to send the equivalent of a text message to a circle of friends, often a smaller one than they have on crowded Facebook accounts.
They can have multiple accounts and don't have to use their real names. They also can follow their favorite celebrities and, for those interested in doing so, use Twitter as a soapbox.