In one of its recent editions, NBC’s “Dateline” aired a report on telemarketing scams that bleed the elderly of their life savings. Three days later, ABC’s “PrimeTime Live” aired a repeat of a similar story.

Duplication on newsmagazines is nothing new, but it’s a situation that could be even more commonplace as the prime-time newsmag landscape grows more crowded.

Come this fall, the four major broadcast networks will offer 10 hours of prime-time news programs.

A decade ago, the networks aired just two hours of newsmags a week - “60 Minutes” and “20/20” - representing just 2 percent of the schedule.

The boom in the genre raises two questions. Are there enough good stories to go around? And, from a viewer’s perspective, how many newsmags are too many?

While they’ve been around for decades, newsmagazines took off as a viable prime-time format for the networks in the late 1980s. For one thing, viewer interest increased. For another, the programs became a cost-effective way to fill time slots normally occupied by expensive drama programming.

Newsmags have always generally cost about half of what networks pay for an hourlong drama. (These days, that’s about $600,000 versus $1.2 million-plus.)

In the early 1990s, the network newsmags kept on coming, until in 1993 they peaked at 10. Last season, the total was down to eight.

“I don’t think all 10 programs on the air will be back on in a year,” said ABC News Senior Vice President Alan Wurtzel. “It’s going to be challenging for the new ones to survive.”

Other insiders are much more bullish - Jonathan Klein, for one, CBS News executive vice president, doesn’t believe TV has reached its limit on newsmagazines, if there even is one.

“When do we reach the saturation point on sitcoms or hour-long dramas?” asks Klein. “These (newsmags) are changing weekly, they’re inexpensive to produce and able to pull in very large audiences week to week, so there’s no built-in self-destruct mechanism.”