The growing importance of the digital factor in the broadcast upfront equation has complicated matters, according to buyers as well as sellers, resulting in an upfront market that could last two months rather than two weeks, writes AdWeek. The networks' digital offerings intend to capture both the audiences spending more and more time with broadband, wireless and other digital applications as well as the resulting flow of ad dollars into the digital space.

Spending on the digital extensions will total roughly 2 percent of the total network ad spend, or around $400 million, but "you can see it exploding in the future," said Leslie Moonves, chairman and CEO of CBS.

Jeff Zucker, CEO of NBC Universal Television Group, said the dollars are secondary at the moment. "I think advertisers are clamoring for ideas." He estimates that NBC's digital offerings could result in $200 million in ad sales, "with that figure tripling over the next few years."