The average amount of time US adults spent at Facebook dropped by three minutes per day last year and will likely decrease by another minute next year, to a total of 37 minutes daily, according to the research firm eMarketer.
The report suggests that Facebook chief Mark Zuckerberg's efforts to focus on safety and remove divisive and hateful content could be having an economic impact.
"Facebook's continued loss of younger adult users, along with its focus on down-ranking clickbait posts and videos in favor of those that create 'time well spent,' resulted in less daily time spent on the platform in 2018 than we had previously expected," said eMarketer principal analyst Debra Aho Williamson.
"Less time spent on Facebook translates into fewer chances for marketers to reach the network's users."
Money taken in from digital ads are the leading source of revenue at Facebook, which has 2.4 billion monthly active users around the world.