Some teens may indeed be anti-Facebook

Facebook's popularity might be on the decline among some teenagers, the company signaled Wednesday.

For younger teenagers, Facebook has seen a decline in the number of daily users, the company reported during its third-quarter earnings call. Overall, usage among U.S. teens was stable between the second and third quarters, but the decrease in daily usage for some was noted early in the prepared remarks of Facebook's chief financial officer, David Ebersman.

It was one of the first times that the social network has identified a decrease in its teenage users. Youth engagement on Facebook is hard to measure because self-reported age data is usually unreliable for younger users, the company said. But, "we wanted to share [the figure] because we get a lot of questions about teens," Ebersman said.

Facebook didn't disclose the size of the decline or comment on it further.

With many rival services vying for younger users' attention, Facebook's ability to keep them on its site is an issue. One area of intense competition is messaging. Facebook operates its own standalone app just for messages, called Messenger, but services such as Snapchat, WhatsApp and Skype are also popular.

Part of the issue might be that everyone seems to be on Facebook now, and teens want their own place to digitally mingle. "Teens don't want to be on the same site as their parents," said Brian Blau, who's an industry analyst with Gartner and a parent of a teenager himself.

Also, a study released by Pew Research Center earlier this year found that the "drama" on Facebook might be driving more teens to one of Facebook's biggest rivals: Twitter.

Overall, on a monthly basis, Facebook grew its number of users to 1.19 billion during the quarter, an increase of 18 percent from last year. Total sales for the company, aided by mobile, were up 60 percent, to US$2.02 billion.

During the call, Facebook said it would continue to build products for people of all ages.

Zach Miners covers social networking, search and general technology news for IDG News Service. Follow Zach on Twitter at @zachminers. Zach's e-mail address is zach_miners@idg.com