It's the advertiser's most reliable commodity, a perennial that never goes out of fashion, but even sex, it seems, must strike the right sales pitch. And fewer men are finding the Penthouse brand appealing.

But with his company, General Media, $52m in debt, Bob Guccione feels that there is "no future for adult business in mass market magazines". The focus has switched to electronic media, in which Penthouse.com means to be a major player.

Penthouse took on Playboy

Despite his company grossing more than $3.5billion over the years, he says he never set out to make a fortune.

The man who first went where Playboy didn't dare, by showing pubic hair, once intended to be a Catholic priest. "But after I went to the seminary, I went through puberty in a resounding way," he said. "Now I am a non-believer."

Instead of a life of celibacy, he married at 18 and became a father, but the marriage soon foundered, and he left his native Brooklyn to become a painter in Europe, hanging out in the caf�s of Paris and Rome. Later, he turned up in London, where he worked as a journalist for a weekly news magazine, London American.

All consensual sex is beautiful

Bob Guccione

While the upmarket lifestyle espoused by Playboy was far removed from the ordinary British male of the 60s, Guccione set out in 1965 to capture the downmarket niche.

The oxygen of publicity immediately inflated his venture when the police arrested him after he had allegedly outraged public decency by sending unsolicited copies of the first issue of Penthouse through the post.

Penthouse helped to end his second marriage, four children later, but on the business front, Guccione went from strength to strength. Throughout most of its life, he has retained firm control of certain key contents of the magazine.

"All the girls are chosen by me and I choose the pictures. I design the layout each month and all the definitive detail. Nobody else would do it as well."

But his third wife, Kathy Keeton, was entrusted with the financial management of the empire.

Kathy Keeton's death hit Guccione hard

When Guccione met her at a nightclub, where she was a "dancer", it was not so much her balletic talents that impressed Guccione as the fact that she was reading the Financial Times. "I would be nothing without Kathy," he said.

Her death from breast cancer in 1997 had a profound effect on the business and private life of Bob Guccione.

But things were going badly wrong before then. One of his costliest gambles was his plan for a $200m casino in Atlantic City; he neglected to obtain a licence in advance and an elderly guest house owner refused all offers to budge as Guccione's four-storey steel structure sat rusting for ten years.

Then there was the episode involving one of his sons, Bob Junior. Having helped him launch a music magazine called Spin in 1985, Guccione Sr withdrew his investment when it began losing money, only to see its fortunes turn around and his son become a multi-millionaire. The two have been estranged ever since.

In the mid-90s, Guccione responded to the growing threat of digital pornography by making Penthouse more explicit, a disastrous move which led to its withdrawal from newsagents' shelves. But in the past year, the new brand of men's magazines, such as Loaded and FHM, have also suffered falling circulation figures.

Guccione built an empire

Living in a limestone mansion in Manhattan, surrounded by bodyguards, dressed like Medallion Man, with a youthful complexion aided by cosmetic surgery, Bob Guccione doesn't drink, smoke or use drugs.

Now, recovering from throat cancer, his $40m mansion up for sale and his art collection, including works by Degas and Picasso, pledged as collateral against loans, Bob Guccione's greatest pleasure still comes from sitting at his easel in the early hours, painting from imagination.

After being sidetracked by Penthouse for decades, soon he may be able to become the full-time artist he always imagined.