"Users can watch for free for 20 seconds. Then they have to pay an entrance fee of VND10,000-15,000 ($0.42-0.63) to get into a live stream room. I pose sexily to entice them to pay me more money in the form of gifts in the app. If they pay enough, I take off my clothes.
"My record is 4,000 viewers in my room at the same time."
Showing off their bodies and getting nude on live streams has become a way for many people like Duong to earn good money.
With cyberspace becoming fertile ground for prostitution, live streams have become a popular channel offering titillating content.
Many apps hire attractive women to live-stream erotic content, which they sell. There is even a list of the top 20 apps of this kind, but most of them are not available on Google Play or AppStore. Users have to search for them on Google and download them from unknown websites.
The apps have hundreds, even thousands, of Vietnamese women as also peers from other Asian countries like Japan and Korea ready to strip for paying customers.
Women working for this app, called "idols", earn money by showing off their bodies and with sex talk.
The women have two streams of income – the salary paid by the company that owns the app and money from viewers. The more money users pay, the more erotic the performance gets.
Duong says: "I do my best to meet viewers' requests. On average, I earn VND500,000-700,000 a day. The company pays me 130,000VND/hour for live-streaming. They pay my salary into my bank account every three days.
"In addition, I receive 50% of the money that viewers pay. Most idols get gifts from viewers. To get the gifts, I pose sexily and reveal more of my body."
If a user likes an "idol" and wants to talk privately with her, the woman usually gives the person her phone number.
A woman nicknamed Bong, who works for an app, said sometimes, viewers pay her VND2-3 million.
"If they pay me a large amount of money, I have to do as they say or I will be punished by my company. The company supervises every live stream room."
The woman said that if a user paid VND500,000 or more, she gives him her Zalo ID. Then they agree on a price for talking privately. The average rate is VND200,000 for 30 minutes of video calling and VND400,000 for an hour.
A user of the app that Bong works for, a man with the nick Hiep Doan, said whenever he opens the app, he sees women livestreaming.
It goes on 24 hours, but the highest viewership is usually in the evenings, he said.
"They take some of their clothes off. If viewers like it, they give the idols gifts so that they keep taking more off.
"I think there are a few hundred women aged between 18 and 30 working for the app."
Doan said he watched the women for fun, but it was quite expensive.
Users need to buy "gold coins" on the app for VND1,000 each, and can use them to pay for "idols" that they like.
Doan said he only spends VND10,000-15,000 each time, but users can end up spending several million dong if they give gifts to the women.
In addition to erotic poses and movements by women, users can also get to watch live sex.
Trieu Quan, not his real name, said couples live-streaming make more money.
He said he has persuaded his wife to perform on the app, and they earn millions of dong by live-streaming their sex for two to three hours.
"We get a basic daily salary of VND200,000-230,000 per hour. In addition, we get around 60% of the money our viewers give us."
They do not have sex right at the beginning of their live shows, only posing sexily at first to lure more viewers.
Quan said he can fix the number of coins for them to start their show. For instance, if he fixes it at 500 coins, he and his wife will have sex once that number is reached.
"I wear a face mask when I live-stream, and so people do not know who I am. Once I got more than VND1 million for 2 hours of live-streaming."
Even if he and his wife did not work for the app, they have sex often anyway. "So why not do it for money?"
Despite being fully aware that what they are doing is illegal, neither the "idols" nor the customers seem overly concerned.
Hanoi police said all prostitution websites are located in foreign countries, making it difficult to collect evidence.
Hiep Doan said: "Users like me are not too worried. But I think these idols may face trouble. It is not clear if the company secures their information. This is illegal, and so these women might be punished if detected."
Duong said she was doing the job because the money is good. She does not think her identity will be revealed because she too wears a face mask while live-streaming.
"I am young and single, and so I am free to do this. I am willing to meet viewers' requests if they pay. The only thing I cannot do is take off my mask because I am a freshman (at a university). I think I will do this until I graduate. If I quit now, I don’t think I can get such a well-paid job again."