One of the few areas I've been convinced that big data is mkaing money is Facebook. They've managed to collect the largest and most detailed direct marketing database in history.
But other sectors? This infographic is full of 500 billion here and 300 billion there, but really, who is going to pay for big data location services? What is it going to do in healthcare?
I didn't find the McKinsey study any more elucidating:
http://www.sebastianmarshall.com/about