Sure, it's got 900 million users—but there's a key demographic that may be slipping away from Facebook's grasp. Young teens tell the Los Angeles Times that the social network no longer boasts much of a coolness factor; indeed, it may have become a "mom thing" (horrors!). "Facebook is just not the big fad anymore," says a 15-year-old. For many of her peers, Twitter, Tumblr, texting, and other mobile apps beat Mark Zuckerberg's site, and give them a little more privacy from Mom and Dad.
Meanwhile, Facebook is huge with older folks: It's got a higher proportion of 50- to 64-year-old users than any other social network besides LinkedIn—almost a quarter—and 3 of 4 US moms using home computers checked into the site in March. But the stats don't bear out the suggestion that teens are sick of Facebook, says an analyst: "Just because teens are using other services like Twitter and Tumblr more—and they are using these services in huge amounts—doesn't mean they're using Facebook less." Indeed, 8 of 10 teens are on social networks, and 93% of them use Facebook. (Read more teenagers stories.)