NEW YORK NBC Universal's USA Network, Turner's TNT and TBS and the Disney-Hearst-owned Lifetime are four of the most popular broad-appeal cable networks on the air today. But a new study from independent media shop TargetCast concludes that many advertisers can save some serious coin -- 20 percent or more -- during the ongoing cable upfront by buying less of those "big four" networks and spending more on a selection of the other top 30 cable networks and still achieve their reach and ratings goals.

And it really doesn't matter which networks, according to Steve Farella, CEO of New York-based TargetCast. The reason: Most of the top 30 networks now cover close to 85 percent of U.S. households, and differences in viewing levels are just fractions of a rating point, he said.

"The average prime-time rating for a cable network is below a one rating," he said. "If you're buying for reach, it really doesn't matter which cable networks you buy."

Yet USA, TNT, TBS and Lifetime tend to have premium prices attached to them because they once really did dominate with their coverage and ratings, Farella said. But as ratings have flattened out and most networks are at or close to parity in coverage, that legacy pricing really isn't justified anymore, he said.

"People gravitate to where they think the audience is -- the big four -- and while they are still the rating leaders, their lead is very small compared to just five years ago. As a result, there is too much advertiser money chasing too few viewers, resulting in unnecessarily high [prices, based on cost per thousand viewers]," Farella said.

The study ran a number of cable schedules targeting women 18 to 49 with various reach goals, in some cases skewing half the weight toward the big four; in others applying only 20 percent of the gross rating point weight to them; and in still other cases picking networks at random. The result: essentially the same reach and GRP delivery in all cases.

The study concludes that with cable reach goals achievable through nearly countless combinations of cable networks, "the buyer is empowered to cast a wide net, leading to improved marketplace pricing as well as open apertures to enhanced consumer receptivity."

Cable network sources, including some at the "big four" cited in the study, took issue with some of its points. "It reads like a sales pitch from a small cable network," said one source.

Another noted that USA had 25 of the top 100 programs in cable for the period monitored in the study, while TNT and TBS had another 23 of the top 100 programs. "You can't compare that kind of engagement and breadth to tuning into the Weather Channel for six minutes to find out what you're going to wear tomorrow," said the source.

Among the "big four," only USA had a comment: "The right brand with the right content and the right environment is what drives value for advertisers."