The worst economic crisis since World War II and the need to sell an ambitious domestic agenda have led President Barack Obama to hold four nationally televised prime-time press conferences in just six months.

Yet those same economic hardships have made the big four television networks increasingly reluctant to preempt their lucrative regular programs at the cost of millions of dollars.

President Obama’s four news conferences, which equal the total held by former President George W. Bush during his entire eight years in the White House, have cost already-hurting television networks an estimated $45 million in lost revenue. 

“It’s a huge financial hit for the networks,” said Tim Calkins, a marketing professor at Northwestern University. “The advertising business is already having a lot of trouble. It’s just compounding the problem.”

Given the tough times in the media business and prevalence of cable news networks, it seems likely the President won’t be able to keep up this torrid pace, especially if his news conferences yield little “new” news.

The networks “have to weigh whether or not it’s worth it. You have to make it worth their while or it’s going to get old,” said Dana Perino, a former Bush press secretary and now chief issues counselor at Burson-Marsteller, a public relations firm.

That cost-benefit analysis is clearly playing a role as the White House was forced to move last month’s press conference an hour earlier to appease the networks and Rahm Emanuel, Obama’s chief of staff, reportedly called the CEOs of several parent companies to encourage their networks to cover it.

At the same time, FOX, which like FOX Business is owned by News Corp. (NWSA), has declined to air each of Obama’s last two prime-time news conferences. Disney’s ABC (DIS), CBS (CBS) and General Electric’s (GE) NBC have all carried each of Obama’s four press conferences.

“I suspect that if we get to a point where the networks feel like it’s too much of a sacrifice or too much of an expense, they will not afford prime-time to presidential press conferences,” said Robert Zelnick, who as a news director and deputy bureau chief for ABC News in the late 1970s helped make these kinds of decisions.

While President Obama's first three press conferences focused mostly on the economy, his July event was used to sell health-care reform and yielded little news. 

By the Numbers

The networks have little to gain by agreeing to carry one of these commercial-free press conferences -- and in fact lose a great deal of ad revenue.

Each hour typically allows for about 15 minutes of advertising time, or 30 ads of 30 seconds each. While prices vary by network and program, each ad can be sold for about $150,000, estimates Calkins. Therefore, each network loses out on about $4.5 million per news conference.

By those estimates, the four major networks have lost a total of $45 million.

“Going forward, we’re going to evaluate these on a case-by case basis, as I think the others are. We obviously want to do our civic duty but we have to balance it,” said one network executive, who wasn’t authorized to speak on the record. “I think [White House officials] appreciate the environment we’re in for television broadcasting.”

The networks have reported mixed results in recent weeks as NBC Universal’s net income tumbled 41% from a year ago and operating income at Disney’s broadcasting unit fell by 34% last quarter. On the other hand, News Corp. offset slumping newspaper revenue last quarter with a 50% jump in FOX News Channel’s operating income.

Priceless Opportunity

While the presidential news conferences are eating into the networks’ bottom lines, they are immeasurably valuable to the White House.

“You literally couldn’t buy that time. To have an hour of prime-time coverage across the networks is essentially priceless,” said Calkins.

Presidents typically use this time to get their message out unfiltered, demonstrate their command for a given topic and offer a sales pitch for an initiative.

“There is a challenge for anybody in marketing: How do you break through today’s cluttered and fragmented environment?” said Calkins. “A presidential news conference covered by all the networks is about as powerful a piece of communication you can get, but if you overplay it, it will go away.”

‘Diminishing Returns’

There’s no question President Obama can command an audience. His appearance on “The Tonight Show” gave Jay Leno his best ratings in four years and an interview on CBS’s “60 Minutes” sent the program to its highest viewership in a decade. And NBC’s two-part series in June, “Inside the White House,” drew a combined 18 million viewers.

“He’s extremely popular and people like to hear from him. He’s absolutely captured the public’s attention,” said Perino.

But the ratings for the prime-time news conferences have slipped as the novelty of President Obama’s presidency wears off.  

For example, the President's July 22 press conference drew 24.7 million viewers, 14% fewer than his April 29 press conference and 50% lower than his first news conference on February 9, according to Nielsen.

“I think diminishing returns can set in unless he carefully allocates his store of charisma,” said Zelnick, who was the executive editor of the Frost/Nixon interviews and is currently a professor at Boston University.

The shifting news business also plays a role in networks’ decisions as half of the big four networks have a pair of cable news and business news networks to cover the events.

“I think you will see a reevaluation by the White House and the networks about what the bottom-line value of these events really are,” said Zelnick.