I received a link from a LinkedIn connection to a very good article on why ad agencies need to rethink themselves:

http://www.linkedin.com/today/post/article/20130119192734-2042198-why-advertising-agencies-must-disrupt-themselves

Disruptive technologies have led to new forms of service-oriented firms that are taking on the kinds of tasks that ad agencies used to have all to themselves. Will ad agencies end up going the way of typesetters and analog film prep houses?