Yesterday's article in the NY Times, "In the Age of TiVo and Web Video, What is Prime Time?" was the latest of many about the changing landscape of broadcast network TV. An underlying question that receives a lot of attention, yet little in the way of clear-cut conclusions: Does broadband video help or hurt broadcast TV networks?

The jumble of conflicting data and opinions on this topic (as well as the related topic of DVRs' impact on the networks) is causing plenty of speculation during this important upfront week of when billions of dollars of networks' ads are bought and sold.

Here's a synopsis of how I think proponents of each would defend their answer:

Broadband video helps: The world is changing - consumers are more empowered than ever and it's pointless to resist. Broadband is a great way to catch up on episodes missed, conveniently sample programs, engender interactivity, transform viewers into viral promoters, etc. More exposure will translate into more on-air viewership. Plus as broadband audience size builds ad revenue will as well. Network programming is and always will be the most watched, most valued source of video entertainment and with broadband opening up all kinds of new revenue opportunities, there's ample reason to be optimistic.

Broadband video hurts: Broadband kills networks' success formula, driving profitable on-air viewership to profitless broadband viewership. It's pie-in-the-sky thinking to believe that broadband revenues will ever catch up. Since only a limited amount of ads can be included in online broadcasts, even the higher CPMs received per ad deliver nowhere close to the revenue per episode per viewer as the on-air model does. All the interactivity and engagement in the world will never offset this shortfall. As more programs move online and viewers can eventually watch these right on their TVs, the shift from on-air to online consumption will only accelerate, causing permanent erosion to the traditional economic formula.

So which is it - are networks helped or hurt by broadband? I think the answer is short-term it helps, but long-term it hurts. In the short-term, there is evidence that broadband expands audiences. For example, The Office's premiere last fall 9.7 million people tuned in, but another 2.7 million watched online.

Expanding viewership is great, but what happens to networks' revenues if next fall 7.7 million watch on-air and 4.7 million online? And 3 years from now, 5.7 million on-air and 6.7 million online? You can count on viewers to gravitate to the optimal viewing experience, and if online further improves, expect more eyeballs to shift. Again, since there are fewer ads online, the only way for total network revenues to keep pace are to show more ads online (see ABC's plan on that front), dramatically raise CPMs and/or dramatically raise viewership. My guess is that even the most optimal mix of these three will not deliver enough to offset on-air's revenue decline.