Got a popular page on Facebook? pay for it to be seen. Got a great unique website? Pay to be seen via Adwords.
Website owners don't link so liberally as they once did because the link graph has been obliterated by "what people think will please Google" rather than linking to things they think other people might like to see.
When I used FB I lost count of the number of times I had to re-jig my setting for displaying content from "most popular" (according to them) versus most recent.
I still find that when I'm browsing Facebook. I see an article with XXXX number of comments and try to see what's newly been said, it's almost impossible- it's like I'm fighting against what new information is available vs their preferred method of displaying things due to the technical limitations of how they store information.