Ad Age:

Time Warner’s CNN and Walt Disney’s ESPN are grappling with the idea that a TV ad should not be judged solely by the number of people it reaches, but also by how many of the people who see it are spurred to share its message with others.

It’s all well and good for a TV network to boast about the ability to lure a sizable crowd, but that’s so old school. Today, marketers want to know what subset of that audience talked about their ad with other people, and if that conversation was a positive or negative one.

…and…

CNN found… that people who make use of multiple CNN venues — i.e. TV and web — are four times more likely to speak about [their advertiser] Lexus than the total population.

Thought not mentioned in the article, social media like Facebook, Tumblr and Twitter could play a big part in a model like this.