I use Facebook for many things. One of those things is to take advantage of the internet hivemind, and get opinions and recommendations for any number of things, from what tech to get, to where to eat. One thing that annoys me a lot, is when someone posts something irrelevant, just so that they can follow the conversation. If memory serves, it used to be that you had to post something – anything – in order to get notifications of what happened in a thread, and it is from this that the practice stems.