It's clear to me that any digital media ( PC or Mobile) will move to exchanges - it's just not possible to unlock the value of digital targeting through the age old media model of people talking to people.
Given the size of the PC world media market and its consequent sloth, I think mobile is most likely to drive this area.
One of the best thinkers on this space is Darren Herman and his latest post is well worth reading - as well as this white paper that Darren points to.
So far we have seen lots of action the sell side of mobile and we expect to see similar activity on the buy side - probably around the exchanges idea. We're very interested to people making movies in this space - please get in touch
Also posted on addictive