http://www.newyorker.com/festival/videos/fevi_video5a
An interesting talk from Malcolm Gladwell who wrote The Tipping Point and Blink.
It's quite long but worth it. (there are links to shorter cuts at the bottom if you get bored) Basically, some people have done research that simplifies music and even films into mathematical formulae that can then be categorised to establish whether or not they will be a hit and they can predict this with 80% accuracy.
interesting Q&A at the end on whether or not this is a good thing
Wrighty