Well, that is a good question don't you think? Especially when you read a blog which claims to give you 'insight for innovation'! Well, the definition that I believe in and that I work with everyday is the definition of my past employer 'The Value Engineers'. They say that an insight is ‘The penetrating understanding of consumers which provides hooks or clues that lead us towards new brand building opportunities’.
That's a pretty damn good definition of insight! Enjoy!