LOS ANGELES — The Oprah Winfrey Network launching Saturday is wary of promising too much of a good thing — Winfrey herself.

In stoking interest in the cable channel, the goal is to exploit Winfrey’s popularity while emphasising that OWN won’t be all Oprah, all the time.

“We really don’t want to be a niche brand. We want to be a mainstream cable” network with appeal beyond Winfrey’s fan base, said Darren Schillace, vice president of consumer marketing for OWN.

“Phase one” of the marketing effort aims to “manage expectations that it’s not 24/7 Oprah on the network,” Schillace said, with Winfrey committed to appearing in at least 70 hours of programming in 2011.

Helping viewers find OWN on the nation’s various and crowded cable systems is another key goal in spreading the word about the joint venture between Winfrey’s Harpo Inc and Discovery Communications.

The effort to position OWN as Oprah-plus doesn’t mean barring Winfrey, or her famous pals, from the premiere hoopla. And it hasn’t led to understated promos for the reportedly $189 million gamble by Discovery.

“Watch our stunning and heart-pounding new video featuring so many stars and so much energy that it will leave you breathless,” gushes the online heart of Planet Oprah, Oprah.com, in a section devoted to OWN.

The media queen herself is central to an OWN ad that debuted in movie theatres, vowing to bring her talk show-crafted message of self-empowerment to the channel’s bigger canvas.

“What if I could take every hero who inspired me, every lesson that motivated me, every opportunity that was ever given to me and give it to you,” says OWN chairman Winfrey, beaming prettily against an unreal blue sky dotted by soaring balloons and puffy clouds.

The spot is backed by the song Own It, written by the Black Eyed Peas’ william for Your OWN Show: Oprah’s Search for the Next TV Star and, in a neat bit of synergy, included as a bonus track on the Peas’ new album.

(Another pop star, Seal, wrote the theme song for Weight of My Mistakes, an OWN series about female prisoners in Indiana.)

Barbara Walters helped out by showcasing Winfrey in an hourlong special that aired early in December, well before the planned spring finale of Winfrey’s syndicated daytime talk show but helpfully adjacent to OWN’s debut.

Then there’s the Winfrey-driven O magazine, which devotes an impressive chunk of its January issue to the upcoming channel and its stars, including the hosts of The Gayle King Show and Our America with Lisa Ling.

Ads have been placed in other magazines, including Vanity Fair, and on radio and cable (“If they watch TV, we want them to watch more TV,” Schillace said of his targets). Billboards feature Winfrey’s image, with one going up in New York City’s Times Square in January, and ads are carried on buses and taxis.

Discovery’s other channels (which include TLC and Animal Planet) are pitching their new sister station. There’s an online blitz with Facebook postings for specific OWN shows, as well as home page takeovers and OWN messages splashed on websites including Yahoo! and MSN.

“In the world of Oprah, from their perspective, they may feel like this is modest and well-controlled,” said Libby Gill, a former TV marketing executive who’s now a brand strategist. Observers may see it as an overwhelming marketing blitz, Gill said, but most of the outreach is “strategically marketed to Oprah’s core fans.”

She terms the approach “really smart,” one that gives the channel room to grow.

The other key part of the marketing equation is the “where” of OWN, which replaces the Discovery Health channel.

To steer people to OWN, available in about 85 million homes, there’s a “channel finder” at Oprah.com with specific area channel numbers.

“On New Year’s Day, I want you to be pointed in the right direction,” Schillace said. That’s a daunting mission. The TV forest is crowded with hundreds of cable channels, and OWN’s launching pad isn’t among the most robust: Discovery Health averages around 250,000 daily prime-time viewers, compared with about 3 million for leaders ESPN and USA. (Winfrey’s talk show is averaging more than 6 million viewers this season.)

As OWN unfolds, expect headliners like Shania Twain and Rosie O’Donnell to get more of the promotional spotlight as the channel attempts to steer attention from its namesake to the rest of its 600 hours of original programming.

Winfrey’s name “is on the front door (of OWN), but I need to maintain that buzz and hype to show there’s other things on this network as well,” Schillace said.

Even a channel topped by the formidable likes of Winfrey must respect the basic imperative of TV, said veteran network executive and producer Garth Ancier.

“At the end of the day, I’m very optimistic that Oprah and Peter (Peter Liguori, Discovery Communications’ COO) can build a stable of shows that will define the network — and networks are always defined by their shows, not their branding,” Ancier said.