While jurors and trial watchers ponder the DNA factor in the O.J. Simpson trial, it's the CNN factor that is worrying people inside the news divisions of the three major television networks.
A news story as big and juicy as Simpson's murder trial would once have attracted huge audiences to the networks' evening news programs. But in the age of CNN, which is available in about two-thirds of the nation's households, the Simpson trial has done the opposite: It has taken viewers away from the newscasts, reducing their weeknight audiences as much as 10 percent.While specifics are hard to come by, those audience losses, if sustained for a few months, could cost the networks hundreds of thousands of dollars a week.
When a big story breaks - or unfolds, as with the trial of the former football star - Americans need not wait to get home and hear a brief account of it from Tom Brokaw, Peter Jennings or Dan Rather and Connie Chung. Instead, they can flip to CNN at their convenience for the latest - often live - coverage. And they can do so from offices, hotels or airport lounges.
The Simpson case is the most dramatic, and melodramatic, example of this phenomenon to date. Because the trial is taking place in Los Angeles, live coverage on CNN and Court TV continues well into the evening in the East and Midwest - often as late as 8 p.m. but certainly through the network news time slots.
And the fact that a trial is a continuing, defined event makes it easy to know when to tune in. With other kinds of dominant news events - a foreign war, an earthquake or other disaster - viewers might be better served by the summing-up coverage offered in a scheduled newscast.
"You just have to look at CNN's ratings and Court TV's ratings," said Andrew Lack, president of NBC News, "especially in the 5 to 7 p.m. Eastern time period, and the correlation is so strikingly clear: O.J. is the only explanation."
CNN's afternoon ratings for the first three weeks of the Simpson trial coverage were 5.1, 5.6 and 6.3 - far above its 0.7 average for that time period.
And the ratings for Court TV were even higher - as much as double those of CNN in the 20 million homes that receive both CNN and Court TV. At the same time, the evening news ratings for ABC, CBS and NBC have declined, collectively, nearly two ratings points from the period in 1994, to an average of 9.4 from 11.3 last year.
CNN's ratings do not directly compare with the networks' because CNN is available in about 64 million homes, while all three main networks reach about 95 million homes. A CNN rating point represents 658,000 households, while a Court TV rating point equals 200,000 households. A network rating point represents 954,000 households.
The Simpson trial has aggravated an overall decline in the network nightly news ratings. The collective audience for network news has shrunk from a 77 share in 1979-80 - that is, network news was on 77 percent of all sets that were tuned to something - to a 58 share last season and a 54 so far this season.
That shrinkage is costly. In the past year, the three networks have each added a minute of commercial time to their nightly newscasts to make up some revenue.
But it is too early to tell how costly the Simpson-related defections will be. Generally, advertisers buy commercial time in news packages that include the evening news and morning shows like "Today" or "Good Morning America" and prime-time news programs like "Dateline" or "20/20."
So as the year progresses, the ratings for these packages may recover enough so that the networks meet their minimum-ratings guarantees to advertisers.
"Still," Lack of NBC said, "if this trial goes on for four or five months and the audience for it remains undiminished, we'll take a significant economic hit."
A media buyer with many clients who advertise on news programs, speaking on condition of anonymity, said: "I think people will get tired of this trial as it drags on. But if audiences stay down or erode further, and the trial lasts until mid-May or June 1, it could cost a network $1 million or more per week."
David F. Poltrack, executive vice president for planning and research at CBS, said, "Even after accounting for the normal pattern of erosion we've been seeing, the network news audiences are down about 10 percent since the O.J. Simpson trial began" on Jan. 24.
The trial also provides daily fodder for tabloid television, talk shows and local newscasts, as well as radio programs - all potential competition for the network newscasts.
"It's a relatively recent phenomenon of our business that people have so many choices at any given time," said Brokaw, the anchor and managing editor for the NBC Nightly News. "I sometimes say, in not entirely mock frustration, that when I started out in the 1960s, there were effectively two network news programs, and at 6:30 p.m. people turned on either Huntley-Brinkley or Walter Cronkite and got their news for the day. And I'd like to have that back again."
The networks will never regain such a near-monopoly. But not all agree that the Simpson trial will accelerate the long-term erosion of the network news audience.
"The O.J. trial is unique in terms of the huge interest in it and the availability of live coverage on a regular schedule," said Lane Venardos, a vice president for news and special events at CBS. "Those two streams converged to make this a larger-than-life event, and I don't think we'll see that again soon."