Facebook Inc.’s is making major changes to its flagship social network, shifting users’ news feeds back toward posts from friends and family and away from businesses and media outlets likely means that retailers that have relied on organic traffic from the social network may take a hit, says one expert.

It may also mean that consumers spend less time on Facebook, wrote CEO Mark Zuckerberg in a post Thursday.

“By making these changes, I expect the time people spend on Facebook and some measures of engagement will go down,” he wrote. “But I also expect the time you do spend on Facebook will be more valuable. And if we do the right thing, I believe that will be good for our community and our business over the long term too.”

The goal, he wrote, is to help Facebook’s more than 2 billion monthly users find content that will lead to more meaningful social interactions.

The changes promised aren’t entirely new—Facebook has been shifting the content on its news feed toward posts from friends and family and away from brands and publications for more than a year. With the latest change, Facebook’s algorithm will prioritize posts that spark back-and-forth discussion or inspire people to share and react. That means posts like a friend asking for advice, recommendations for a trip or an article that prompts interaction, according to a post by Facebook’s head of news feed, Adam Mosseri.

The move may lead some brands and retailers to pull back a little on their Facebook ad spend if, as Zuckerberg said, users do spend less time on the platform, says Melissa Parrish, a Forrester Research Inc. vice president. However, it could also produce some benefits for retailers that produce creative, well-targeted ads.

“With fewer irrelevant public posts, ads will stand out more in the short-term,” she says. “That could mean that advertisers will see even more engagement with their ads until users get used to the new news feed and start to tune the ads out again.”

A large part of brands and media companies’ strategies is to post articles and videos from their pages to engage consumers items that aren’t considered “meaningful interactions” between people. Downplaying those posts from brands and businesses may put revenue at risk, said James Cakmak, an analyst at Monness Crespi Hardt & Co.

“There will be less opportunity to expose Facebook users to brands,” Cakmak said. “But those opportunities to get in front of users will be that much more impactful if it’s more selective.”

Though the shift back to personal interaction may not mean fewer paid marketing spots in users’ feeds, any drop in engagement and attention may still translate to fewer ad dollars. Travis Parker Martin is the co-founder of Bootkik, a Calgary-based startup that attributes the majority of its growth to its Facebook presence. More than 90% of the education startup’s marketing budget has been spent on Facebook ads. Given Thursday’s announcement, Martin said he plans to significantly decrease that.

“Only a few weeks ago, we decided that we might be better served growing our presence on YouTube. We were frustrated that the returns were diminishing on Facebook.” Martin said. “This confirms that we will have to pursue other channels.”