Using CBS as an example, Keane said the online video audience for one episode of "Jericho" boosted the show's TV ratings by almost a full point: from 4.2 to 5.1. While Keane made no mention of it, this extra audience is especially valuable for a show like "Jericho," which has struggled to build a larger audience. The show's hardcore fans saved the show from cancellation once, but it's hanging by a thread--and another ratings point may help.

Citing another example from CBS, Keane said that while the Grammys attracted 16.9 million TV viewers--down 15% from the previous year--it also generated 7.9 million online video streams and 4.9 million page views.

Of course, it's a two-way street; TV programming also boosts online traffic. Keane said CBS Interactive closely tracks the relationship between shows and online behavior. Showing a chart that overlaid TV and online audiences, Keane said online traffic spiked in a fairly predictable way following certain kinds of programming, allowing CBS to refine its programming.

Most important, Keane added that the online activity didn't cannibalize the broadcast audience--meaning that advertisers can add to frequency with linked online campaigns.

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