Americans will spend more than half of their social networking time on Facebook this year, but growth of user engagement with the platform is set to slow, a new report shows.
Of the 43 minutes a day U.S. adults spend on social media in 2016, 22 minutes will be spent on Facebook, according to eMarketer.
But by 2018, while U.S. adults will spend three more minutes a day on social networks, they will only give an extra minute of their time to Facebook.
Between 2013 and 2018, time spent on social networks as a whole will grow 5.9 percent, while time spent with Facebook will grow 5.3 percent—meaning Facebook lags slightly behind the category in growth in usage time.
"Facebook has…been facing competition from other fast-growing social networks like Snapchat, and cannibalization from its own property, Instagram," eMarketer forecasting analyst Monica Peart, said in the report.
"With other social networks investing heavily in making video a core feature of their platforms, their collective time spent will begin to challenge that of Facebook."
Facebook's growth has been driven by mobile with time spent on the social network on smaller devices set to grow 12.9 percent between 2013 and 2018, while desktop and laptop engagement will decline 7.5 percent.
The social network's rising engagement time has been driven by the focus on video content in recent times. Facebook's latest figures from November put its daily video views at 8 billion.
Slowing engagement will be a concern for Facebook particularly after recent media reports that internally, the company is worried about people sharing fewer personal updates like statuses or stories about their life.
But if Facebook's latest earnings are anything to go by, the company is unlikely to be worried. Monthly active users on the platform were 1.65 billion at the end of the first quarter of 2016, while advertising revenue hit $5.2 billion, a 57 percent year-over-year increase.
It's also important to remember that Facebook also owns Instagram, Messenger and WhatsApp. In the earnings call last week, chief executive Mark Zuckerberg said people around the world spend on average more than 50 minutes per day on Facebook, Instagram and Messenger, and that's without including WhatsApp.
But competition is fierce for ad dollars as ephemeral messaging app Snapchat is trying to stamp its authority on the mobile video space, while Google's YouTube continues to remain strong. Snapchat recently said that it gets 10 billion daily video views and has been pushing new ad products to get brands on board.