Every so often, fears emerge that Facebook (NASDAQ:FB) has a teen problem, losing younger users to rival social media platforms. Oftentimes, those younger users are simply transitioning their usage to Instagram, which isn't a concern since Facebook owns that platform, too. Snap (NYSE:SNAP) remains strong within this demographic, though, and Snapchat could continue stealing younger users from Facebook this year.

After all, Snap did just post a better-than-expected increase in daily active users (DAUs) last quarter, while Facebook posted its first-ever decline in U.S. DAUs.

Instagram interface on iOS and Android

Image source: Instagram.

Facebook could lose 2 million younger U.S. users

eMarketer reports that younger users are ditching Facebook "at an even faster pace than previously expected." For the first time, less than half of all U.S. users in the age range of 12 to 17 will log in to Facebook from any device on a monthly basis.

Facebook's monthly active user (MAU) gains are mostly concentrated in older demographics, according to the report. The company had 239 million MAUs in the U.S. and Canada last quarter, flat on a sequential basis. eMarketer's estimates relate specifically to the U.S., where it believes Facebook will hit 169.5 million total MAUs (all ages) this year. eMarketer's predictions for Facebook's U.S. users this year aren't good:

Age Group

Estimated 2018 Change

11 and younger

(9.3%)

12 to 17

(5.6%)

18 to 24

(5.8%)

Data source: eMarketer.

The analytics company notes that this is the first time it has predicted a decline in Facebook U.S. users within those age groups. In terms of absolute numbers, Facebook could lose 2 million users ages 24 or younger. While Facebook's official age policy requires users to be 13 years or older, the age limit is easy to bypass. Facebook recently launched Messenger Kids, specifically targeting younger users under the age of 13 in an effort to hook them early.

Instagram is expected to add 1.6 million users ages 24 or younger, but Snapchat could garner 1.9 million users ages 24 or younger. By the end of 2018, eMarketer expects Instagram to have 104.7 million U.S. MAUs and Snapchat to have 86.5 million U.S. MAUs. Instagram has 800 million MAUs worldwide, and Snap does not officially disclose MAUs at all.

How will Snapchat's redesign impact user metrics?

There is a curve ball, however. Snap is in the midst of rolling out a major redesign for its core Snapchat app, and all users should receive the new version by the end of the first quarter. The redesign is intended to address long-standing criticisms that Snapchat is hard to use, as well as make it more approachable for older users. However, there could be some backlash within Snapchat's core younger demographic. Early user reviews were overwhelmingly negative.

Just last week, a social media hoax suggested that Snapchat would revert back to the original interface if a user obtained 50,000 retweets. That hoax has now been retweeted 1.3 million times (no free chicken nuggets required), suggesting that there is considerable user interest in Snapchat going back to the way it was.

Social media users tend to overreact to platform changes, so it's conceivable that the vocal backlash won't manifest in any meaningful way in terms of user metrics, and if Snapchat can strengthen its position within older demographics with the change, it might be worth it.

Evan Niu, CFA owns shares of Facebook. The Motley Fool owns shares of and recommends Facebook. The Motley Fool has the following options: short March 2018 $200 calls on Facebook and long March 2018 $170 puts on Facebook. The Motley Fool has a disclosure policy.