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. Read more