When you are having a conversation with someone over facebook, but your conversation is consisting of only posts on each other's walls. Then randomly after about 3 posts, the other person decides to continue the conversation by adding a comment to your wall-post, instead of creating a new post on their wall, thus giving the illusion of them being more popular when one looks at their wall.
"what the hell dude, we were having such a great wall-post discussion and then you had to become a wall-post-whore. i do not approve."