The verdict is in after months of speculation: younger teenagers are checking Facebook less often on a daily basis.
But chief financial officer David Ebersman's acknowledgement of that fact during the social network's third-quarter earnings call wasn't exactly a revelation for the marketers who've been watching teen flight from Facebook for some time.
But whether it's the beginning of a more pronounced departure of Facebook or merely a statistical blip remains to be seen.
Mr. Ebersman didn't elaborate on the age range of those younger teen users whose daily activity had dropped off. Users have to be 13, or enter a 13-year-old's birthday -- to sign up for a Facebook account. He also said that younger users' activity was hard to report with accuracy "because self-reported age data is unreliable" for that demographic.
There's a range of opinion among marketers about whether teens splitting time between Facebook and other messaging apps like Twitter or Snapchat is of real consequence. Of course, Facebook owns Instagram, which teenagers are wild about. The $1 billion acquisition last year looks increasingly wise in light of Mr. Ebersman's announcement.
Teens less active
Digitas's VP-social marketing Alex Jacobs said the agency conducted a study of Facebook engagement aggregated across clients and found that younger millennials in their late teens are less active on the social network. While that hasn't impacted spend yet for clients, it has bearing on how much organic content they'll publish on the social network.
It also makes experimentation with social-networking apps like Snapchat -- a medium where users can send vanishing messages, which doesn't have ads yet -- more of a priority. Taco Bell used Snapchat in the spring to tell its followers that it was bringing back the Beefy Crunch Burrito.
"You need to keep pace with [millennials]," Mr. Jacobs said. "That means a lot of exploration and a lot of trying new things."
On the other hand, PayPal's head of social media Dave Peck said that the decline of Facebook usage among younger teens will have no impact on his Facebook strategy. "Find me a better network. You take half of what Facebook has, and it's still more than anyone else has," he said. "It's not like I can advertise on Snapchat."
Though engagement among teens may be down, Mr. Peck's contention that Facebook still has more teen users than anyone else is borne out by research.
According to Pew Research Center, 94% of teens between 12 and 17 surveyed this summer have Facebook accounts, compared to 26% who have Twitter accounts. And a spring study by TRU (a youth research unit owned by WPP) found that 75% of teen respondents reported visiting Facebook in the prior 30 days, compared to 32% who said the same of Twitter.
"Facebook has peaked, but it remains an incredibly important utility," said Scott Hess, senior VP-human intelligence for Spark SMG. "It is the center of their social-networking universe even as they use Instagram and Snapchat and Kik and everything else."
There are any number of reasons for teens to be less enamored with Facebook, even if they still maintain a profile and check in periodically. Their parents are probably there, for one thing. There's also the fact that teens seem uniquely disposed to private messaging, evidenced by the long tradition of passing notes in classrooms. (While Facebook has a separate "Messenger" app, it's really an extension of the core service, which is more public-facing.)
Only when teens go to college does the need arise for a more public persona.
"Early on we thought Facebook would be a big hit with the kids because they all lied about their age to get on it, but now there are other platforms out there that teens can use for the [more private] ways they really want to communicate," said Ian Schafer, CEO of Deep Focus.
Mr. Schafer doesn't foresee teen-oriented marketers leaving Facebook, since its massive reach hasn't budged, and the ad targeting is good enough that they're unlikely to be wasting many impressions.
So what can Facebook do if it doesn't want its teenage user base to erode? Continued investment in Instagram is a given. (Its users weren't accounted for in Mr. Ebersman's reckoning of the drop-off of young teen usage.) And another acquisition could be on the menu, according to David Gutting, VP-strategy director at Barkley.
Snapchat would seem like an obvious target, but with a capital raise of up to $200 million that would value it between $3 and $4 billion now reportedly in the making, it would be expensive. And Facebook is only now starting to generate revenue off its Instagram purchase with the launch of its ads last week.
Ultimately, Facebook will have to hope that those young users start visiting daily again once they get to college. The social network's overall market penetration puts it in a good position.
"Facebook is not like Mountain Dew, which is something you stop drinking after 26 or 27," Mr. Gutting said.