This was supposed to be the year that network executives burned their rule books.

Several network titans proclaimed last spring that the TV industry’s traditions and economic model were as dated as episodes of "Dallas." Viewers, they said, crave sizzle! Fewer reruns! And 52 weeks of original programming!

Leslie Moonves, co-president of Viacom Inc., apparently didn’t get the memo.

Good thing.

Moonves’ CBS network boasts seven of the top 10 shows among the audience that advertisers prefer most: 18- to 49-year-old viewers. That’s quite a feat for an operation long derided as the "geezer network" because of its older-skewing audience.

Instead of concentrating on younger viewers, Moonves continues to champion the old-fashioned model of a broadcast network as a "big tent" that attracts all viewers. So far, CBS is the only network this summer to post ratings gains, albeit a modest 4 percent compared with the same period last year.

"It’s pretty amazing," Moonves said last week. "We’ve been the most conservative, but quality programming and slow and steady wins the race."

General Electric Co.’ s NBC — while maintaining its first-place mantle in the key demographic group — is down 13 percent over last summer. News Corp.’ s Fox Broadcasting Co. is down nearly 20 percent. Walt Disney Co.’ s ABC network is off by about 4 percent, and its losses could have been even larger if not for its ratings boost from the well-watched matchup between the Los Angeles Lakers and Detroit Pistons in the National Basketball Association championship.

What’s more, in a summer when other network executives have been relieved to remain flat in their ad revenue hauls, CBS has been muscling prime-time rate hikes of as much as 10 percent.

"CBS is standing pat with the old business model, and it’s working," said Brad Adgate, research director for advertising company Horizon Media.

Advertisers closely watch the summer show-down to help handicap the fall season, when more money is at stake. Advertisers are betting that when the fall season begins in September, CBS will make an even bigger ratings surge.

Unlike its flashier rivals, CBS has stuck with reruns of its established shows this summer, such as "CSI: Crime Scene Investigation."

And instead of experimenting with new unscripted offerings, Moonves opted to bring back some favorites, "The Amazing Race" and "Big Brother." New installments of those shows quickly scored well with viewers.

By comparison, rivals have launched new shows, including "The Jury" on Fox, "Next Action Star" on NBC and "The Ultimate Love Test" on ABC. Some have failed to stir viewers’ passions.

"In a risky and inconsistent business, Les Moonves has been the most consistent," said Bill Cella, chairman of the media-buying giant, Magna Global USA. "He gets it."

As a result, Moonves has ensured CBS a profitable year.

The TV business has long been built on a simple financial formula.

Networks order a season’s worth of shows — typically 22 episodes — and run each episode twice during the year. On the first airing, the network recoups the fees it pays for the shows by selling advertising time. On the second airing, the network rakes in the money.

But, in recent years, network executives have watched a summer exodus of viewers who turn to cable channels rather than watch reruns.

Executives have found that even their most critically acclaimed dramas, such as NBC’s "The West Wing," ABC’s "Alias" or Fox’s "24," don’t repeat well. That has prompted some network chiefs to respond with year-round programming spiced up with reality shows.

But, Moonves said, that "trend might not be working out so well... . The cost model doesn’t work if you have too much original programming in the summer. Advertisers don’t pay as much for time in June and July as they do in October and November."

What’s more, Moonves said, "Reality programming ain’t as cheap as it used to be."

CBS’ higher ratings have been driven by a mix of proven shows.

CBS executives say that its strategy to rely on reruns in the summer helps recruit new viewers.

For two summers now, CBS has watched the ratings soar for reruns of Thursday’s missing persons drama, "Without a Trace," which launched in fall 2002 in the shadow of NBC’s ratings giant "ER."

On Thursday, the show marked a 19 percent ratings increase over last year among 18- to-49-year old viewers. This summer, among all viewers, "Without a Trace" reruns have been beating "ER" reruns by more than 7 million people.

CBS’ newfound strength in the late programming hour is helping to boost the fortunes of CBS-owned TV stations, by funneling more viewers into the late local newscasts.

Stations make most of their money from local news.

Moonves said other networks can try to rewrite the rules of the business all they want.

But, he said, "The system is broken only if your shows don’t work."