We all know how big contextual advertising is... driven largely by the success of the Google AdSense platform. I just caught wind of a new application called ToneCheck (http://www.tonecheck.com) which claims to be able to estimate the overall tone of a sentence in your emails prior to sending them out.<p>Thoughts on whether this has successfully been done before? There's plenty of sharks out there in the marketing world who have been trying to perfect this for years. I mean, what better way to target and analyze your users than by dissecting their emails and being able to check for tone and sarcasm to reduce false positives/negatives.