Within minutes, Krina's video chat room is full of adoring users from all over the world, imploring her via instant messages to take her clothes off. She doesn't, and instead replies with jokes and teases customers by dancing in front of the camera.

Another window pops up on her monitor, a sign that a user has paid for a one-on-one session. After a few minutes of small talk, the user asks Krina if she can undress for him. She complies, stripping slowly, whispering suggestively to her client. Once naked, Krina pleases herself, to the delight of the man. When both of them have finished - after several minutes of moaning and groaning - the client congratulates her and quickly abandons the chat.

Still naked, Krina lights a cigarette and checks to see how much she just made: US$110 for a 25-minute show.

"I don't know much about him, but he is a good customer," says Krina, exhaling smoke. "He is from the US and comes around five times a month."

A former university student and waitress, Krina has, for three years, been a professional camgirl at Live Cams Mansion, the agency based in the house. She works eight hours a day.

The camgirl phenomenon, the roots of which can be traced back to 2000, has grown exponentially thanks to improved internet speeds and cheaper technology, revolutionising pornography and becoming the fastest growing sector within the adult entertainment industry. Major adult cam sites such as LiveJasmin, Chaturbate, Flirt4Free and Streamate feature hundreds of women online at any one time. While users can see and chat with the models for free, they have to buy credits in order to watch them perform. Private one-to-one sessions typically cost between US$2 and US$9 per minute. The cam site collects payment from the credit cards of clients and splits the takings with the women.

Camming has become hugely popular thanks to the interactivity between customer and model. Depending on the preferences of both user and camgirl, private shows can consist of anything from a kinky fetish session to a simple conversation. Customers feel they are being let into the intimate lives of ordinary women, which is encouraged by the "girl-next-door" look adopted by many of the models and the fact that they generally work in bedrooms.

The typical customer is in his 40s, 50s or 60s and, according to manager Adrian Ionescu, Live Cams Mansion's clients have included a famous American rapper, a Nobel Prize winner and a Spanish national football player (real names are not used but it is up to the client whether or not he turns on his own webcam). Customers tend to be men who are unable to relate to women in real life; who feel that cheating on their wives online is no sin; who are curious; or who lack the time needed to cultivate personal relationships.

The activity is so profitable and accessible (all you need is an internet-connected PC and webcam) it has attracted tens of thousands of models from every corner of the world, from students and single mothers to middle-aged housewives and even "grannies". Camboys have entered the scene as well, catering for gay and female audiences.

Although most camgirls in the West operate from their own homes, in Eastern Europe studios are providing women with equipped rooms, promotional tools and web traffic in exchange for a share of their profits.

Thanks to its large number of good-looking women, high-speed internet and a cost of living that makes camming earnings particularly attractive, Romania has become the uncontested capital of this trend. Local media and dedicated online forums estimate the country is home to about 700 studios, within which 40,000 local, English-speaking models cater for more than 150 million users all over the world - even in ultra-conservative Saudi Arabia (although, for domestic legal reasons, customers in much of the Middle East must use software that masks their IP address).

Their work remains taboo in general society, but Romanian women take to the web to pay for their studies or support their families, although the vast majority are attracted simply by the money to be made from a low-skill endeavour. A camgirl can make anything between €900 (HK$7,800) and €3,000 per month in a country where the average salary is about €400.

"It's an easy way to make money and at the same time you don't really force yourself with responsibilities," says Krina.

Born in a village in southeast Romania to a poor family of farmers, Krina had her first contact with camming at 19, she says, when she joined a studio in the city of Constanta.

"I still remember my first private show; I was very frightened and nervous," she says, laughing. "A client asked me to strip and please myself. While I was doing it the only thing I could think about were the vegetables I had to buy to prepare a soup for dinner."

Krina only stayed at the studio for a few months. She decided to become a full-time camgirl three years later, when a death in her family and subsequent troubles at home prompted her to abandon university and her €250-a-month waitressing job to move to Timisoara, to "video chat", as the activity is known in Romania.

"I arrived here not having friends, not having anything, but I needed to change something in my life," she says.

Three years since then, Krina has become the "queen" of Live Cams Mansion, which hosts nine camgirls, all in their 20s and in the care of the portly Ionescu, 36. According to Ionescu, Krina is the one with most potential and one of the most sought-after women on Flirt4Free (the women of the house feature on this website as well as on livecamsmansion.com, which lists many more than the nine women living here). She is also the face of the agency on promotion material.

The house has a distinctly homely atmosphere and feels cut off from the outside world. Time passes in an endless cycle of shows, cigarette breaks and conversations by the pool. The women spend much of their spare time here; most of them come from outside Timisoara and the mansion has helped them to settle into their new lives and forge strong friendships.

Lynette Smith (nicknames are often chosen to resemble those of porn stars or sound American, as many clients log in from the United States), the youngest of the group, is trying to balance camming with her studies and hopes her family and friends will never find out what she does for a living; Bonie Blue, of Slovak origins, is also known as Supergirl, after a client asked her to put on a superhero-like costume, pretend to save him from a burning building and then seduce him; Domina Monserrat is a mistress who caters for all types of fetishes and is thinking about moving to Italy to find a "slave" to live with; Kendra Blu is a former gymnast, a Romanian hope for the 2008 Beijing Olympics whose sporting career was cut short by a back injury.

They were all attracted to camming by the money.

"I have been in this business for more than 10 years and I have yet to find a girl who does this because she likes it," says Ionescu.

Being a camgirl is harder than you might expect. Because only about 10 per cent of the users who visit the chat rooms are willing to pay (the rest are commonly identified as "beggars"), competition to attract customers is fierce and women must sometimes wait for hours for a show to be requested.

"At times it is very boring, but you can't just sit on the bed and read a book," says 20-year-old Smith. "You have to be ready and make customers feel you are there."

On the other hand, when their chat rooms are filled with dozens, sometimes hundreds, of users, models can have a hard time coping with the many requests, questions, comments and, sometimes, insults. According to Amalia, the human-resources manager in charge of job interviews at Live Cams Mansion, only two out of 10 women make it past the first month. "This job is nerve-wracking," she says. "Girls need nerves of steel to do it."

Managing the periods when clients are few and the pressure to earn mounts can also be difficult, as can hiding emotions from the public.

"Even if you have had a bad day, or you are desperate because you haven't earned anything for a while, you cannot show it," says Natali Rose, a 25-year-old from Timisoara who started working at Live Cams Mansion last October. "You need a lot of self-control, because every emotion that you have is visible on camera."

One of the most difficult parts of the job is having to cope with the stigma associated with camming. Although camgirls are among the most successful professionals in Romania, the shame connected with the activity prevents them from feeling proud of their achievements.

A brief stroll around the campus of the West University of Timisoara offers a glimpse of how camming is perceived by the wider society. A blunt young student calls camgirls "whores" and says she recently cut ties with a friend who became one. A group of older women say they don't know much about camming, but fear it might be the first step towards more dangerous activities, such as prostitution.

Camgirls stress that there is no physical contact with clients, there is no human trafficking connected with the work and they can refuse to perform anything they don't feel comfortable doing.

"I am not ashamed about what I do," says Rose. "There are many girls doing this, generations are changing and young people don't have such a bad conception about it anymore."

The daughter of estranged parents, Rose lives in her mother's house; her mother works as a restaurant cook in Italy. Although she was aware of the industry for a long time, Rose summoned up the courage to attend a job interview at Live Cams Mansion only after talking with a friend who was already performing.

"I used to be shy, now I feel more self-confident about myself and my body," she says. "I socialise much more easily, both online and in real life."

Rose hasn't yet told her family what she does for a living but plans to do so in December, when she will have the chance to talk to her mother face to face.

"I expect her to get angry at first," she says, her fingers playing with her red braids, "but I am sure she will understand after seeing how many things I can afford now."

Many models come from villages where work opportunities are few and, like Rose, a significant number come from broken homes or have parents who work abroad; reduced family control is no doubt a factor when deciding to go before the webcam. The women generally don't have much education, nor a clear plan for their future. Most learned a little English at school, which is polished on the job, and many speak a little Spanish and Italian, which are similar to Romanian. Almost all of them say they would like to set up their own business but, by their own admission, lack the skills to manage their finances properly.

"I am worried because most of them don't have goals in life and just think about today," says Ionescu. "They come to work only when they need money and when they gain some, they spend it all."

Women working from a studio must guarantee they'll spend a minimum number of hours online - in the case of Live Cams Mansion that is 170 hours per month or a certain amount of money earned every day - and respect a timetable, because they occupy a workstation that is shared with other models in shifts.

The industry has a very high turnover and young women burn out quickly. Spending so much time in a closed room isolated from the outside world takes a mental toll, with many models dropping studies, friendships and relationships to concentrate on work. Those who haven't disclosed what they do have a particularly hard time explaining their absences to families and boyfriends, especially when they work night shifts.

"It is very tiring; these long hours online prevent me from doing anything else. I don't have friends outside of here because I can't manage my time," says 27-year-old Baby Vanessa, the eldest camgirl at the mansion and the only one who seems to like the job for what it is.

From a city in Transylvania, Vanessa has always dreamt of appearing in Coca-Cola adverts and on covers, she says. Raised in a middle-class family by her teacher parents, she earned both a college and a master's degree in business management and describes herself as a "very smart girl".

"I had the chance of being anything I wanted, but I got stuck into this. It's like an addiction," Vanessa says, with a hint of regret in her voice. "I love to see users worship me. I have clients logging in from work just to say hello."

Still heartbroken by a relationship that ended three years ago, Vanessa badly wants a family, she says, but cannot picture herself leaving a job that satisfies the exhibitionist part of her personality.

"I like to show myself, to dance, to be sexy and crazy, but at the same time I feel I have disappointed my family," she says. "They had huge expectations for me and I could be much more than what I am now."

As camming is not a particularly satisfying job for the vast majority of performers, Ionescu often motivates the women with success stories like that of InnocentKat, a classy 25-year-old who cammed for six years, earning up to US$25,000 a month.

"I started to have more clients when I paid more attention to the setting of my room, my clothes, the quality of my webcam," says InnocentKat, who works as the Romanian representative of Streamate and has dropped by Live Cams Mansion to discuss business with Ionescu. She puts her success down to the care she took over the small details and her understanding of psychology. "I was constantly mixing things up. One day I was fully covered in an abaya [a robe-like dress], another day I could be wearing only lingerie."

Over time, InnocentKat came to understand the mindset of regular clients and to take control of the conversations.

"You have to show them you have a strong personality. I wouldn't undress or do anything in private if the clients had not asked me politely," she says. "Moreover, I never lied. If I had a boyfriend, I would tell them. Some clients were going crazy, speaking about committing suicide because they were in love with me."

To attract and keep clients, camgirls need to be engaging, communicative and good listeners. They must be aware of and satisfy their clients' needs. The more developed these qualities are, the more a camgirl will be able to run her own show, like an actress, without focusing too much on the sexual aspect.

"Nowadays there are a lot of private shows that are about conversations and online friendships, rather than sex," says Jamie Rodriguez, brand manager at Flirt4Free. "Being a pretty, smiling girl in front of a camera was probably enough 15 years ago, when the industry was so new, but it is not sufficient now."

It is common for camgirls to lie to customers who claim to have fallen in love, as they tend to be the best clients and build relationships with the girls that go beyond the erotic.

"You can be more open with them, especially if you don't feel like performing a show," says Rose. "One of my clients lost his wife a few years ago and never recovered from the shock. He would buy a private show only to cook for the two of us, as if I were her."

Vanessa says she had a Portuguese client who offered to wire her €10,000 and one in Texas who recently hinted at marriage.

Many customers fantasise about meeting their camgirl in real life; an unlikely scenario as models rarely reveal any personal details, for security reasons.

"There are all kinds of weird people out there and you don't want to find a stalker or a psycho in front of your house," says Krina.

Live Cams Mansion's Arianna Smith, 26, once received a tip of US$6,000 from a Spanish customer.

"I remember staring at the monitor in disbelief. He was on the other side of the screen and I couldn't stop crying for the joy," she says.

Arianna used the money to pay for breast implants, which, she believes, will help her earn even more. She makes about US$3,000 a month but is convinced she can reach US$10,000.

"I don't consider myself particularly smart, but I am a very strong woman. You need to fight every day for what you want," she says, black eyes shining with determination. "I want to buy my own house and car. Camming will help me achieve my goals."

The fact that camgirls will always remain a virtual dream is something most customers must surely know, deep in their heart, but fantasising about this forbidden, impossible love is maybe what they need to cope with their real lives.

"This is part of the job, we are selling illusions," says Ionescu. "If they want to buy them, it's not our fault."