"In total, we made changes that reduced time spent on Facebook by roughly 50 million hours every day", Zuckerberg said.
Facebook fell as much as 5.2 percent to $177.10 in late trading, after closing in NY at $186.89.
Chief Executive Mark Zuckerberg (pictured) may have fed fears of lower engagement in prepared remarks, in which he said Facebook is focused on making sure it "isn't just fun to use, but also good for people's well-being and for society". But the company, which also competes with news outlets for ad dollars, has also faced criticism that it isn't doing enough to combat misinformation from going viral. With the goal of distributing high-quality news, Zuckerberg said Facebook would roll out user surveys to gauge the trustworthiness of different media outlets.
The social network also worked with local news publishers through the Facebook Journalism Project in the past year.
Marketing specialists in social media along with travel agency owners have been complaining for years that changes made by Facebook to news feeds algorithms make it harder to promote businesses on the platform and reach new customers with free publications.
The Menlo Park, California, company said in a news release that it identifies local publishers as those clicked on by readers in tight geographic areas.
Facebook stock fell today after its CEO, Mark Zuckerberg, said that people are spending 50 million fewer hours on Facebook a day. In a note to investors earlier this month, Laura Martin, an analyst at Needham & Company, said that Facebook's shift towards more content from friends may keep potential regulations aimed at the company from gaining momentum. Its popularity in the USA appears to have waned, though, with a decline from 185 million to 184 million daily domestic users from last quarter.
Facebook has become more self-critical since revealing a campaign by Russian Federation to spread political discord around the 2016 presidential election that reached an estimated 150 million U.S. users on Facebook and Instagram.
Facebook users and news outlets should expect yet another update.
People consistently tell us they want to see more local news on Facebook. Facebook is altering the formula that determines what shows up in people's news feeds to favor status updates from friends and family that spark more "meaningful social interactions".
This overload, as he estimates, is due to video material and other content that has gained large dimensions in Facebook over the past 2 years.
The company also reported almost $13 billion in fourth quarter revenue Wednesday, up 47 percent from the same time previous year, and an all-time high for the company.
Facebook had warned earlier this month that tweaks to its news feed feature would result in a hit to user engagement and it has also been affected by changes to the way it shows videos.
Also sounding alarm bells, Facebook experienced its first-ever decline in daily active US and Canadian users to 184 million from 185 million in the prior quarter.