NBC Plans "Second Screen" Experience for Free Super Bowl Web Stream - Peter Kafka - Media - AllThingsD

And in NBCís case, it is packing the Webcast full of extra camera angles and other goodies, including a feature that will let you rewatch every Super Bowl commercial once itís aired. The assumption is that youíre holding the TV remote in one hand, and controlling your laptop with another.
NBC already does a version of this with its Sunday Night Football broadcasts during the regular season, and the network says it draws between 200,000 and 300,000 unique viewers per game (thatís the source of that Vikings-Saints screenshot, above).