Here is a follow up interview with Raj Kadam, CEO of Viralheat API whom we have interviewed on the Sentiment Analysis API here. In 2012, Viralheat had about 30 billion calls over all its' APIs. Viralheat just announced a new API called Human Intent API.
Here is an interview with Dr Stuart Battersby, Chief Technology Officer and Founder of Chatterbox.co - a sentiment analysis engine that utilizes machine learning (yes that all familiar buzz word) to social media conversations (even more prevalent buzz words). However what makes Chatterbox.co stand apart from social media err,chatter is it's clever use of hard core computational performance of machine learning with insightful and creative business use cases.