The internet has witnessed the conversion of analog advertising dollars into digital advertising pennies (credit due to Jeff Zucker at NBC (GE) for “coining” that metaphor). Despite the fact that a viewer is always just a “click away” on the internet, online advertisements command only a fraction of the cost of far less measurable media – like print, radio, and television. Consider this: an advertisement on MySpace (NWS) might cost $.25 to show to 1,000 people ($.25 CPM), versus $25 for 1,000 readers of Time (TWX) magazine ($25 CPM). In the good old days of performance-less advertising, engagement didn’t really...