Watch out, publishers: a nightmare scenario on Facebook may soon be a reality.

The social network last week officially launched its secondary news feed called Explore. The feed generally features posts from Facebook Pages users don't follow. News Feed, meanwhile, hosts posts from friends and Pages users do follow.

But that's not true for everyone. In six markets, Facebook has removed posts from Pages in the original News Feed and relegated them to another feed, Filip Struhárik, editor and social media manager at Denník N , wrote. That means Facebook's main feed is no longer a free playing field for publishers. Instead, it's a battlefield of "pay to play," where publishers have to pony up the dough to get back into the News Feed.

It's a stark change from how media outlets have grown with Facebook. Publishers like BuzzFeed's Tasty and NowThis grew via distributing viral posts and videos on News Feed, as Ziad Ramley, former social lead at Al Jazeera English, wrote. While companies had to employ social media managers, they could generally rely on them sharing content without paying to boost it.

That game could be over, creating a nightmare situation for publishers while Facebook hopes it leads to more advertising revenue.

Living off organic Facebook reach?

You’re in for a tough time

That free party is over.

News Feed in 2018 will be for paying guests only. — Matt Navarra ⭐️ (@MattNavarra) October 21, 2017

For now, the setting is only available in Slovakia, Sri Lanka, Serbia, Bolivia, Guatemala, and Cambodia, according to Struhárik. A Facebook spokesperson told Struhárik it's a test but declined to share information on the timing.

“With all of the possible stories in each person's feed, we always work to connect people with the posts they find most meaningful. People have told us they want an easier way to see posts from friends and family, so we are testing two separate feeds, one as a dedicated space with posts from friends and family and another as a dedicated space for posts from Pages," a Facebook spokesperson wrote in an emailed statement to Mashable.

"To understand if people like these two different spaces, we will test a few things, such as how people engage with videos and other types of posts. These tests will start in Sri Lanka, Bolivia, Slovakia, Serbia, Guatemala, and Cambodia. We have no current plans to roll this out globally," the statement continued.

The change hasn't been good for publishers. Over the past couple days, publishers saw interactions on posts by the 60 biggest Slovak Facebook Pages fall dramatically.

Image: Filip Struhárik/crowdtangle

With multiple feeds, Facebook creates more places to hold users' attention.

Of course, the numbers could improve. Some Facebook users may not even know Explore exists or at least not be inclined to click to a new feed yet. But over time users could be motivated to navigate between the two feeds. The concept is quite similar to what Snapchat offers via Stories (individual accounts) on one feed and Discover (publisher content) on another. Snapchat's Discover section is far more curated than Facebook's wealth of Pages, however.

With multiple feeds, Facebook creates more places to hold users' attention. The hope for Facebook is more money. With multiple feeds, Facebook creates more places to hold users' attention and therefore show them ads. That's important for Facebook as it balances ad load — the amount of available real estate for ads — across its platform.

Facebook has already begun changing how it displays professional content. Facebook Watch is a separate tab for watching long-form, original video. Publishers told Mashable they appreciated Facebook's Watch initiative at launch since it incentivized them to create high-end content rather than relying on clickbait videos.

Navigating yet another feed won't be easy for users or for publishers. News Feed's algorithm has always been unpredictable, and now it's unclear how Explore could fair.

Update October 23, 7 p.m. ET:

Facebook released a blog post after publication of this article clarifying that they “currently have no plans to roll this test out further.” Facebook said the same thing in the statement included in this article.