In coming days, Facebook users will see fewer posts from publishers, businesses and celebs they follow.
Facebook's revamping of the Feed is meant to ensure more "meaningful interaction" on the social network, Zuckerberg said in his post.
With its stock up 48 percent over the past 12 months, Facebook has been a major driver of a technology rally that has propelled the S&P 500 to record highs. To that end, the company says it surveys tens of thousands of users each day to get a more complete picture of what people want to see.
While the changes could hurt Facebook's business in the short term, happier users could make for better profits over the long term. Facebook depends on those ads to make its money, making the phenomenon one Facebook is said to have been worrying about for years.
"On the other hand, passively reading articles or watching videos - even if they're entertaining or informative - may not be as good", reveals Zuckerberg. Video posts on Facebook have also increased in the past two years, further contributing to this state.
According to Facebook's announcement, the company will give priority to posts that it predicts will drive more engagement through shares and comments, and that less content from company pages will show up at the top of users' feeds. People will likely spend less time on Facebook as a result, the company says.
The announcement caused Facebook shares' worth to drop by nearly 4.5%, instantly wiping $3.3bn off Zuckerberg's fortune.More news: Area braces for winter weather
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It is a known fact that public content has exploded on Facebook.
Publishers in particular - many of whom have relied on Facebook to build up huge audiences and achieve viral gold - are likely to take a hit from the change.
Facebook tweaked its news feed in 2014 to clamp down on "clickbait", posts with grabby headlines like "you won't believe what happened next" yet ultimately disappoint.
Oh, the researcher at Korea Press Foundation, said it was too early to say whether the latest measure would reinforce Facebook's "filter bubble" effect or not.
Facebook was widely criticized for its passivity amid the avalanche of false information that invaded the feed of US users during the presidential elections of 2016.
"Since there's more public content than posts from your friends and family, the balance of what's in News Feed has shifted away from the most important thing Facebook can do - help us connect with each other", adds Zuckerberg.
John Ridding, the chief executive of the Financial Times, warned on Friday that the domination of online advertising revenue by search and social media platforms was putting pressure on media firms. Dotface's videos about a South Korean mother giving a hug to young sexual minority people who could not tell their parents about their sexual orientation struck a chord with viewers around the world, accruing 5 million views and many shares, comments and likes.