When Taiwanese maths teacher Chang Hsu started a YouTube channel to teach calculus in March last year, he needed a strategy to attract students. So he began uploading his educational videos to the kind of websites which college kids tend to watch: Pornhub and Onlyfans.

“Because too many calculus instructional videos have been uploaded to general platforms, in order to make more people notice us we uploaded the videos to adult websites,” Chang, 34, told HKFP. “We did not originally intend to teach on adult websites, it was just a marketing strategy.”

Photo: Pornhub screenshot.

The strategy has worked. Chang, who has uploaded 226 videos onto the adult film sites since May 2020, has garnered around 24,000 subscribers on his YouTube page.

His videos on Pornhub, which range from three minutes to almost an hour, have been viewed a total of 1.9 million times.

“This method is definitely an effective way to attract public attention… it has also definitely attracted students, because most of my students are college students,” he said. “Most college students go to these adult websites, so a large percentage of them will see me, they will have an impression of me.”

Chang told HKFP that, although his videos aren’t the most popular on Pornhub — his account is ranked 685th — they nonetheless make an impression. “I believe that many people may forget the adult actresses they have seen, but they should always remember the maths teacher from Taiwan who teaches calculus on an adult website.”

“I can probably be considered the biggest ethnically Chinese calculus teacher on Pornhub.”

‘Very amusing’

Reaction to Chang’s unexpected videos has been mixed.

“People all over the world think I’m just joking. Most of them think this kind of behaviour is very amusing. I rarely see comments criticising me,” he said.

Photo: Pornhub screenshot.

His students, meanwhile, are mostly blasé about his initiative. “I have never seen any comments that are from my students, or even parents. Because my students are all grown-ups, they won’t really feel any animosity to my uploading videos to adult websites, because it is also likely to be part of their daily lives,” Chang said.

He has, however, drawn some scorn from other cram school teachers. “I’m usually criticised by other cram school teachers. They may dislike me because their students switched to my courses because of my marketing strategy and quality teaching content. But they are still a minority, so it doesn’t bother me that much.”

‘Every means to survive’

While Chang’s unconventional approach has brought him success, his entrepreneurial efforts to expand his teaching business are not just a gimmick, they are a lifeline.

Chang told HKFP his new teaching channel was an effort to claw his way back from large debts and deep depression.

In January last year, the cram school he founded was shuttered without his knowledge by a former employee he had entrusted with running it. The employee then opened a new school in the same building.

“His behaviour caused me to instantly lose all sources of income. I was already burdened with a lot of debts, so [the former employee’s] behaviour actually caused very serious harm to me. I even wanted to commit suicide for a while,” he said.

In an effort to recoup his losses, Chang, who has taught calculus for over a decade, revamped his old cram school into a studio to film educational videos. With the help of other teachers, he began building the brand “ChangHsuMathsTeacher.”

Photo: Pornhub screenshot.

The first days of operations were a flurry of attempts to gain maximum exposure, he said, as he was on the brink of bankruptcy. His team shot 100 videos within the first month. Other projects included two continuous 10-hour videos to solve 100 calculus problems.

He has also shot a 32-hour video teaching high school calculus.

Almost two years on, Chang’s online teaching platform has over 1,000 students.

“More and more international media are reporting about us, but most of them focus on our current success or interesting marketing strategies. But I think the more important thing is that we were actually trying to save ourselves from failure, so we tried every means to survive. Uploading the video to the adult website is just one of the various methods we tried.”

He told HKFP he hoped his story will inspire others not to give up hope.

“I hope that through this hidden part of my story, I can give more people the strength to let them know that maybe if they stick to a certain path, they will see the dawn of hope.”

If you are experiencing negative feelings, please call: The Samaritans 2896 0000 (24-hour, multilingual), Suicide Prevention Centre 2382 0000 or the Social Welfare Department 2343 2255. The Hong Kong Society of Counselling and Psychology provides a WhatsApp hotline in English and Chinese: 6218 1084. See also: HKFP’s comprehensive guide to mental health services in Hong Kong.

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Rhoda Kwan in Taiwan

Rhoda Kwan is HKFP's Assistant Editor. She has previously written for TimeOut Hong Kong and worked at Meanjin, a literary journal. She holds a double bachelor’s degree in Law and Literature from the University of Hong Kong.