I am always amazed by a) how important Facebook is to how much traffic a news story can get online and b) how little journalists know about how Facebook chooses what goes where on a page, your newsfeed for example.
Facebook uses an algorithm called Edgerank. The formula that Edgerank uses is this one:
Plus, admittedly, a touch of randomness.
It means that postings that are in line with what you normally like and interact with rank higher on your page.
Older stuff falls to the bottom. Edgerank is trying to put the things you care enough to comment on the highest.
What does this mean to journalists?
You should be pushing people to comment on your posts-not just like. Not just click. Comment!
So the most valuable posts are the ones in which you try to involve the readers in a discussion on Facebook.
Read a LOT more on Edgerank here.