WWW- There’s no question that pornography is a booming business in the United States.

Despite a decline in the sales and rentals of porn videos, it’s still a multibillion-dollar industry, and the rise of amateur videos, revenue-sharing Web sites such as XTube.com and technological advances bringing pornography to your cell phone and beyond means that porn is as prevalent as ever.

The Adult Video News Media Network, a trade publication, estimates that the industry earns $14 billion annually, and the Web site www.pornsunday.com estimates there are 4.2 million pornographic sites online with 40 million visitors daily.

The adult film industry may be innovating and evolving, but is porn really just another form of entertainment, or is it an addiction?

Is porn dangerous or harmless? Is it necessarily degrading to women, or could it be empowering?

In 2006, “Porn King” Ron Jeremy and “Porn Pastor” Craig Gross embarked on a series of debates about porn in America, organized through Wolfman Productions. They have held 16 debates to date on the pros and cons of pornography, including debates at college campuses such as Ohio State University, Colorado College and the University of Missouri.

On Feb. 15, “Nightline” co-anchor Martin Bashir moderates the “Nightline Face-Off: Is America Addicted to Porn?” in New Haven, Conn., during Sex Week at Yale University.

[Start watching the debate Thursday Feb. 21 on ABCNEWS.com, plus watch the full story on “Nightline” Friday, Feb. 22 at 11:35 p.m. ET]

Last spring, the first “Nightline Face-Off: Does God Exist?” pitted actor and evangelical Kirk Cameron and his partner at the Way of the Master against two self-proclaimed atheists.

The second “Nightline Face-Off” features Ron Jeremy and Vivid porn star Monique Alexander on the pro-porn side, while Craig Gross and former porn producer Donny Pauling argue the anti-porn side.

Jeremy, 54, has appeared in more than 1,800 adult films and is listed in the Guinness World Records for “Most Appearances in Adult Films.”

He is also the author of an autobiography and has appeared on the VH1 reality show “The Surreal Life.”

“I think porn is healthy,” Jeremy said in one XXX Porn Debate. “It’s all part of that wide world of entertainment, nothing more, nothing less,” he added.

Jeremy’s goal? “We want happy, healthy people watching porn recreationally,” he said at one debate.

Jeremy will be joined by 25-year-old porn actress Monique Alexander, who is under contract with Vivid Entertainment. Alexander became a dancer at the age of 18 and has been working in the adult industry since 2001.

“I am perfectly fine,” Alexander said, adding that she thinks “porn is a lot more acceptable now.”

She believes pornography actually gives women more power and control. “We get paid more money than the men,” she said. “We have more say so.”

Alexander said couples approach her to thank her for her films because they have helped spice up their relationships.

“It’s just sex,” Alexander said.

Five years ago, Craig Gross, a seminary-trained evangelist, created an online fellowship called XXXChurch.com, originally intended to serve as a resource for Christians who were struggling with pornography. The Porn Pastors, as Gross and his co-founder call themselves, now target their preaching at members of the porn industry, encouraging them to turn away from the sex industry and seek salvation.

Gross said they are obeying the great commission at the end of Matthew’s Gospel to “go and make disciples of all nations.”

“I think that God is using people that work with XXX Church to carry about his message, to carry out his plan,” Gross told “Nightline” in a 2007 interview.

The Porn Pastors believe porn is dangerous for society — delusional for men and disrespectful to women. They say the fantasy of porn inhibits people from building and sustaining meaningful relationships.

“When you get in a relationship with a real woman, you’re not going to know what to do,” Gross said during one debate.

“Porn is a lot easier than sex, especially now with the Internet,” Gross told “Nightline.” “You can get it when and where you want it … and so what we see is people resort to the pornography, even when they are married and they could have a great sexual relationship.”

Joining Gross in the “Face-Off” will be former porn producer Donny Pauling. Pauling worked in the industry for nearly a decade, producing thousands of hours of material. But in September 2006, two years after he was first contacted by XXXChurch and began to re-examine Christianity, Pauling said he turned away from the industry and turned his life over to God.

On his Web site, donnysramblings.com, Pauling writes that he was driving home after landing a new and lucrative deal when “God just reached out and touched me,” and “I instantly lost all desire to produce porn.”