by Lewis Mitchell, University of Adelaide
Think about what you shared with your friends on Facebook today. Was it feelings of stress or failure, or perhaps joy, love or excitement?

Each time we post on social media, we leave traces of our mood.

Our emotions are valuable commodities, and many companies are developing automated tools to recognise them in a process known as sentiment analysis.
https://theconversation.com/explainer-how-the-internet-knows-if-youre-happy-or-sad-77401
http://www.abc.net.au/news/2017-05-23/sentiment-analysis-how-the-internet-knows-if-you-are-happy-sad/8550392