Facebook: Want to see more posts? You must pay the friendship toll.
"Do you want to see more posts?
The more friends you add, the more posts, photos and videos you'll see in News Feed."
If you scroll down the News Feed far enough, you will hit the bottom of the feed, as a new limit on how much wall content you can see has been established. Also, you will be greeted with the message above.
Must be a new feature to encourage more friendship.