• by Wayne Friedman , Staff Writer, April 6, 2007

It was like compulsive military service: For years, TV viewers were expected to watch reruns to help keep the TV business strong. Now some viewers are going AWOL.

Ever since networks started offering Internet viewings of their shows, they also came up with research that said all those new airings of prime-time shows had no effect on traditional TV.

But now it seems that’s only half true:  That is, there’s no effect from Internet viewing of original prime-time shows.  But, yes, there has indeed been an effect when it comes to networks reruns.

In some instances, dramas could retain 80% of their original ratings in reruns. Now those numbers are down to 60% or less. This is especially true for shows like CBS’ “CSI” franchise -- shows that are self-contained and can be easily watched in reruns versus that of serial dramas like ABC’s “Grey’s Anatomy” or “Desperate Housewives.”

Vince Manze, the new scheduling honcho at NBC, suggested that perhaps networks should go back to doing mini-series again -- no doubt in an effort to keep original programming in the minds of prime-time viewers over several nights in a row.

Scheduling does indeed have a lot to do with it. In the past, all the networks would air reruns at the same time -- so those shows weren’t as hurt as now. Now, reruns can air against high-powered original programs -- which can crush shows.

But there’s conflicting news here: Over the last three years, there has reportedly been little broadcast rating erosion among prime-time shows. If that were true, it could only mean that original shows have been doing really well, pulling more weight as reruns sink in viewership.

Fox’s “American Idol,” now in its sixth season, has a lot to do with it, as it has steadily climbed in ratings throughout its entire run. “Idol” also occupies a sizable part of Fox’s prime-time schedule in the spring.  Other reality shows like “Dancing with the Stars” also contribute with multi-day per week big ratings. But is all this enough?

The questions concerning reruns are: If I really missed a specific show that I want to see, what would I do? Wait for the summer or some non-sweep time periods to catch that show? Or, just immediately go online and find the exact show I’m looking for?

That’s an easy answer. But what isn’t easy for the networks is how they’ll continue to monetize prime-time shows with lower ratings on reruns.

The whole network system depends on reruns -- even in this age of reality shows that aren’t repeated at all. Networks can run scripted shows as many times as they want -- for free. And with that comes advertising sales for still-big dollars.

Can the Internet make up the difference? Right now those Internet viewings are priced much higher per-thousand viewers than on traditional TV. But the total out-of-pocket prices are still small.

And of course, serialized dramas -- which always repeat at lower numbers than self-contained dramas -- will continue to be a network staple. And all this will create more drama in network executive suites.