IBM: Watson tone analyser
When it comes to AI, IBM has some incredible tools. The Watson tone analyser is way of extracting sentiment from data. Typical usage would usually be social data that a business needs to analyse for responses about their entity, or a product release for example.
There are many more applications for this type of data analysis than just metrics on your own business. For example, you can monitor competitors mentions, trends in certain keywords, or even monitor data live for catching angry customers.
We used sentiment analysis on bulk social media data, and were able to filter by the types simply. This enabled us to monitor bulk data in an easy way.
For gathering sentiment on huge amounts of data easily, and accurately.
This is not a free service.