Hotels are in the business of keeping guests satisfied—and they’re going out of their collective way to make sure they are.

Every Hilton guestroom now features trademarked Hilton Serenity Collection Bedding. W Hotels provide in-room massages from Bliss Spa. And Marriott (MAR) has what they’ve dubbed the mSpot, a redesigned room equipped with iPods, laptop hookups and a 32-inch high-definition television.

Judging from revenues, the initiatives are working for big hospitality players. Starwood Hotels (HOT), parent of the W and Westin chains, brought in just under $6 billion last year alone. Hilton took in just over $8 billion. Marriott: $16 billion.

But beyond plush beds and spa services, the real cash cow is pay-per-view porn, responsible for hundreds of millions of extra dollars annually. (Was One Night In Paris ever shown in a Hilton property? It would, at minimum, explain Paris’ family’s astonishing lack of shame following the video’s “appearance.”)

An Associated Press report said that adult films generate 60 to 80% of total in-room entertainment revenue, edging overpriced liquor and snacks on offer in the mini-bar.

The family values crowd isn’t thrilled about the statistics. Kathy Shepard of Hilton told the AP, “Really ultraconservative groups try to target the hotels in their zest to eliminate porn. In their zest to have their personal morals prevail, they’re eliminating choice for others.”

That’s not the way Phil Burress, a self-described former porn addict and head of the Cincinnati-based Citizens for Community Values, sees it.

“In-room obscenity is the dirty little secret of the hotel industry,” he said. “If you stay in a hotel that offers pay-per-view obscenity, it is the same as spending the night in a XXX-rated bookstore, and who would want to stay there?”

One book you won’t find at any adult bookstore -- Gideons Bible -- sits in the top drawer of every nightstand in every hotel room across America. You’ll also find ready access to Horny Housewife Auditions, Eighteen and Corrupted, Hustler’s All-Girl Slumber Party and Bi Bi American Pie.

Roger Conner of Marriott explained that none of the adult programming offered by the chain is illegal, and depicted its availability as standard in hospitality. “In-room movies are a revenue stream,” he said. “This is a business matter.”

Notwithstanding, conservative group Morality in Media once gave an award to the company’s founder, J.W. Marriott, for his efforts to fight pornography.

But as far as Phil Burress is concerned, the issue transcends business. Maybe even the First Amendment. “As more and more of these hardcore titles become available, we’re going to have sexual abuse cases coming out of the hotels,” he lamented. “Hotels are just as dangerous as environments around strip joints and porn stores.”

Oh? U.S. Department of Justice statistics show an 85% decrease in sexual violence over the past 25 years. One researcher points to a negative correlation between pornography and criminality.

Tired of fighting City Hall, Phil Burress changed direction. If he couldn’t force adult films out of hotel rooms, perhaps he could steer people away from the hotels that offered them. So he established CleanHotels.com, a guide to hotels that don’t make adult films available.

I took a look at CleanHotels.com and noticed that one of their family-friendly recommendations is New York City’s Chelsea Hotel.

I can just see it now:

“Look, kids, it’s Room 100. That’s where Sex Pistols bassist Sid Vicious stabbed his girlfriend, Nancy Spungen, to death!”

“And here’s the room where Charles Jackson, author of The Lost Weekend, committed suicide in 1968!”

“Let’s go down to the desk and ask the clerk which room Charles Bukowski stayed in.”

Thank God there’s people like Burress to look out for us.