Dive Brief:

• Facebook's user base in the U.S. will grow 0.9% this year, reaching 169.5 million, according to new report from eMarketer. Though the platform's growth is plateauing, Facebook remains the most-used social media network for all age groups, except for one: teens. 
• This year, Facebook users age 12-17 will number 11.5 million, down from 12.1 million in 2017. By 2022, eMarketer expects teen users of Facebook will drop to 9.3 million. In contrast, Snapchat, which overtook Facebook as the top network for teens in 2016, is expected to add 1.2 million new users age 12-17 by 2022 and will remain the dominant platform for the age group. In 2018, 16.4 million teens will use Snapchat and 12.8 million will use Instagram, which Facebook owns.  
• For millennials, Facebook is the most-used social network with 58.5 million expected to use the platform this year. Instagram comes in second with 43.3 million millennial users. Among Generation X, 45.1 million will use Facebook this year, but those figures are forecast to fall to 43.8 million by 2022.

Dive Insight:

The eMarketer report is the latest to show younger users' preference for Snapchat and Instagram over Facebook. Both of the image-sharing app's Stories features remain a strong draw for teens, and these platforms have built out marketing tools to better monetize the disappearing photo and video collage format.

In June, Instagram expanded its Shopping tool to Instagram Stories, for example, and Snapchat similarly has begun to allow shopping within Stories. Facebook has tried to translate the success of Instagram Stories, which copies the feature of the same name from Snapchat, to its core platform. Facebook Stories initially saw little traction when it launched in 2017, but the platform reported 150 million daily active users and started introducing ads to the service in May. 

Still, it will likely be hard for Facebook to address overall slipping interest among emerging segments like Gen Zers. EMarketer earlier this week reported similar findings in regards to consumer trends in the U.K., where Facebook's user base is forecast to increase just 2% to 32.7 million this year. That leveling signals that younger social media users are forgoing Facebook and instead opting for other platforms, per eMarketer.     

Research continues to show that members of Gen Z also have an overall complex relationship with social media. Thirty-four percent of Gen Zers said they were permanently leaving social media and 64% reported taking a break from the networks in a survey from Hill Holliday's Origin group released in March. Respondents said the platforms made them feel anxious and depressed, and also cited privacy concerns and a barrage of negative information and content. 

Facebook has been at the center of much of those discussions due to high-profile data privacy controversies like the Cambridge Analytica scandal. While the social giant has been working to improve transparency — it last week tapped HP's Antonio Lucio as CMO, who will help spearhead those efforts in the company's marketing — eMarketer data show that its user base continues to stagnate. 

Facebook's revenue growth is also slowing. The company reported that its Q2 growth rate decelerated about 7 percentage points from Q1 in a trend that's expected to continue.