A survey of young Net users  between 13 and 25 by Posterous cofounder Gary Tan has turned up some very surprising, and potentially explosive information. While 55% of 13- to 18 year-olds and 52% of 19- to 25 year-olds liked Facebook for social networking interactions, supporting the conventional notion that Facebook is the world's dominant  social net, 61% of the young group and 57% of the adult group preferred Tumblr.
Instagram, Facebook's huge and controversial  billion-dollar acquisition, was liked by just 21% of the young teens and 11% of adults. Even Twitter fared badly, with 22% of teens and 17% of the young adult group liking it.
Facebook's prosperity is linked to monetizing its billion-user community's social interactions. But while it unquestionably leads the field in the social networking world, its future is far from assured--all it would take is a runaway success from a newer challenger and many of its users may click away. Tumblr has been demonstrating aggressive  growth  in recent years, at a pace that outstrips its rivals.
Do you see yourself using Facebook (or Twitter, or Tumblr for that matter) in five years? Or will something new come along?