Los Angeles- Bob Meyers is learning fast that technology and libido can be a treacherous mix.

As Playboy Enterprises Inc.’s president of media, Mr. Meyers is scrambling to sustain the profitability of the company’s U.S. television business. Leading the assault on the business is video-on-demand technology, which threatens to make obsolete the pay-per-view networks that Playboy has dominated for a decade, largely thanks to several big acquisitions orchestrated by CEO Christie Hefner.

Playboy’s sales from domestic TV — the company’s largest business — last year fell 16%, to $82.5 million. Fears of continued TV weakness led four analysts to downgrade their Playboy stock ratings to “hold” last month. Earlier this month, Chicago-based Playboy gave several TV executives their walking papers, a spokeswoman says.

The problem isn’t just sinking sales. As viewers move away from Playboy’s networks — industrywide, sales of adult pay-per-view on cable are estimated to have fallen 28% since 2005 — the company risks getting stuck with the huge costs of running those networks around the clock. In the past, the cost structure served as a barrier to entry, giving Playboy a competitive advantage. But with video-on-demand technology, smaller rivals such as Hustler TV and lesser-known distribution companies can compete with Playboy one skinflick at a time.

“It changes the dynamic completely,” Mr. Meyers says. “Now all I have to do is send a bunch of movies to the cable operator and they store them in their servers. It’s a completely different business.”

And a booming business: By the end of this year, Monterey, Calif.-based Kagan Research LLC forecasts, sales of adult on-demand videos on cable will have risen 55% since 2005, to $437 million from $282 million.

The boom has attracted rivals known for more graphic programming than Playboy.

Consolidation has given cable operators more bargaining power with suppliers. According to Michael Kelman, a Bala Cynwyd, Pa.-based analyst with Susquehanna Financial Group LLLP, operators can take up to a 90% cut of sales.

Mr. Meyers is charged with helping Playboy navigate this new adults-only landscape. Like many Playboy executives, he’s more familiar with the corporate than the porn world. At 51, this is his first foray into adult entertainment after years as an executive at business news channel CNBC and broadcast syndicator Westwood One. In his spare time, he says, he likes to play golf and spend time with his family.

But under Mr. Meyers, Playboy has dropped single-X-rated channels in favor of more explicit ones. One of them, Shorteez, is described in Playboy marketing materials as “a hard and fast ride that gets to the good stuff faster.”

Still, Playboy’s competition problem is apparent to any Chicago Comcast subscriber. On a recent Tuesday night, a standard Comcast digital cable guide listed four Playboy-owned pay-per-view channels out of five adult channels available.

But of 10 adult on-demand offerings, only three came from Playboy. The others were served up by competing porn distributors, including the Erotic Network, or TeN, owned by Playboy’s biggest rival, New Frontier Media Inc. of Boulder, Colo.

Mr. Meyers, who splits time between Los Angeles and New York, says his short-term plan is to reduce costs in the declining pay-per-view business without harming it. But in the long run, he acknowledges, Playboy may have to dump the pay-per-view business, which would be a stunning reversal from a decade ago, when Ms. Hefner spent $105 million to buy leading porn network Spice TV.

“You have to make some decisions about where you want to place your bets,” Mr. Meyers says, although he cautions that an exit from pay-per-view isn’t imminent: “We haven’t nearly crossed that bridge yet.”

Meanwhile, to goose the top line, Mr. Meyers sees a “strong future” for “subscription” on-demand service on the flagship Playboy TV network, which allows viewers to tune in anytime for a regular fee. Also in charge of Playboy’s Internet offerings and namesake magazine, he’s looking at better ways to cross-promote all the company’s products.

But that’s tricky on TV, where several brands — such as ClubJenna, Spice:Xcess and Shorteez, for example — are set apart from the Playboy name and bunny logo.

“The Playboy brand doesn’t play a role there at all,” Mr. Meyers says. “So the question becomes, do brands matter in that space? The answer is, probably not as much as they do in other spaces, or as much as they do in the Playboy space.”

That’s not to say that some adult brands aren’t thriving in the new on-demand world.

“Our broadcasting revenue grows every year,” says Michael Klein, president of Hustler TV parent LFP Broadcasting LLC, a Beverly Hills, Calif., company owned by porn tycoon Larry Flynt. “Larry is very happy.”