It’s called Social Engineering, Facebook will use the additional data gather when you “love” something or are “Sad” about another post to learn more about you. This will help FB tailor to your news feed which affects how news organizations distribute information and can influence how political campaigns present there messages. Among other thing it’s meant to keep you engaged and keep clicking. The conspiracy theorist might say it’s another form of surveillance others might think that there trying to measure your emotions.. For the whole break down see the full story HERE