Sentiment analysis (also known as opinion mining) is the process of determining the emotional tone behind a series of words.
It is used to gain an understanding of opinions, emotions and attitudes expressed online via social networks, blogs, forums, news sites, reviews and more. It extracts insights from social data and is being adopted by large and small organisations across the world.
It is extremely powerful - a negative comment on social media can be retweeted by millions of people. Naturally companies want to defuse any anger or misconception quickly - without social media analytics and sentiment analysis this wouldn't be possible due to massive volumes of data.
If companies are able to pick up negativity early, it can often work in the company's favour.