Facebook CEO Mark Zuckerberg Flickr, Andrew Feinberg Facebook's change to its news feed will be scrutinized closely and anxiously by advertisers, especially those who have brand pages with thousands or millions of followers.

The new change effectively puts an extra roadblock in front of boring content by placing content that has been proven to be more interesting on top of it.

That's going to hurt brands — and people — whose Facebook pages are boring.

And, frankly, that's a lot of brands.

When brands have hundreds of thousands of followers, even small changes to a page's "reach" among its audience can result in huge numbers of gained or lost exposure across Facebook.

Facebook has previously been forced to deny that it rigs its news feed "Edgerank" algorithm to restrict the reach of advertisers.

In fact, only about 15% of followers will see any given post on a Facebook page. If advertisers want guaranteed exposure beyond that, they must either create super-interesting content that will naturally go viral or they must pay to promote posts. Or run ads.

The new change to News Feed will re-up older stories to the top of any users' news feed as long as those stories have gotten a lot of engagement from the users' friends. The intent is to surface stories that are probably interesting to you even if you missed them the first time around. Facebook said the new system wil reward interesting advertisers with more likes:

In a recent test with a small number of users, this change resulted in a 5% increase in the number of likes, comments and shares on the organic stories people saw from friends and an 8% increase in likes, comments and shares on the organic stories they saw from Pages.

But for every winner, there must be a loser.

Every time a "hot" story is re-surfaced in your news feed, a colder one will be pushed lower down in your feed. Posts from boring brands (and friends) will likely get seen less.

So Facebook has essentially made the incentives for advertisers more extreme than they were before: