Hotaling herself had endured the worst type of violence. Shortly after the death of her father, when she was three years old, she was sexually abused for the first time, with further occurrences between the ages of five and seven. She went to school in Palm Springs, but by the time she was 18, she was on the streets selling sex and soon became a heroin addict.
In 1989, after 21 years in prostitution, Hotaling decided she had had enough. She turned herself in at the nearest police station and insisted that she be put in jail, where she stayed for six weeks, almost dying during drug withdrawal. She soon began to devote her life to helping other women. First working with Aids sufferers, in 1992 she founded Standing against Global Exploitation (Sage), a San Francisco-based centre offering services to help women out of prostitution.
Furious that street prostitutes continued to be arrested and blamed for their circumstances, Hotaling decided to try to educate people living in neighbourhoods most affected by the trade. She began meeting regularly with community leaders, explaining that the women were not there out of choice, but that the kerb crawlers were. It was then that she decided to do something about the demand side of prostitution.
Ironically, it was her collaboration with the police officer who had arrested her countless times in the 1980s for soliciting, Lieutenant Joe Dutto, that enabled her work with sex buyers to take off. She contacted him after hearing of his concern about the spread of HIV and other sexually transmitted diseases in the city, and, by then armed with a degree in health education from San Francisco state university, offered her skills.
Hotaling devised a programme that was to become known as the John's school, which came to be replicated across scores of cities in the US, Canada and the UK. Formally known as the First Offenders of Prostitution Program (Fopp), charges against first offenders were dropped if they paid a fee and attended a day-long course, including sessions run by former prostitutes, on the realities of the sex trade. Most of the fees went to help women attend the Sage programme.
"I was scared," she said about the first time she ran Fopp. "I knew they would hate me. I never thought in my wildest dreams they would get anything out of it. At the end of the programme they were all crying." Very few men who attend Fopp are known to reoffend, and its existence has enabled a change in emphasis to focus on the demand for prostitution as the cause of the problem.
In recognition of her work with Sage and Fopp, Hotaling received more than 20 awards, including Oprah's angel award in 2001, presented to her on air by Winfrey herself. She also advised governments on how to tackle trafficking and prostitution and addressed conferences all over the world.
Asked in 1997 how she managed to work with women who have complex problems, she replied: "It's like caring for orchids. They die so easily. But you take the dead-looking stem to someone who knows orchids and that person can look at the root and say, 'Look! There's still a little bit of life here.'"
Hotaling never married. She is survived by her mother and brother.
• Norma Hotaling, campaigner, born 21 July 1951; died 16 December 2008