HONG KONG -- On a recent weekday evening, Selina, a writer from mainland China who works overseas, entered an online chat room titled "The Politically Incorrect Group" on the new social media app Clubhouse.
She ended up spending five hours in the Chinese-language chat room discussing topics ranging from political systems in general to human rights in China with hundreds of people from Hong Kong, Taiwan as well as on the mainland.
The Silicon Valley-founded platform, as described by Selina, who requested that her full name not be used because of the sensitive nature of the discussions, is a rare space where people from the three places can speak freely outside of Beijing's great internet firewall.
Indeed, there is concern among some Chinese users that a ban on the app by mainland authorities could be imminent.
"It's interesting to hear so many liberal voices coming from the mainland, where people typically are censored and underrepresented on China's internet," Selina said, citing a heated debate over protests in Hong Kong and issues spanning the Taiwan Strait. "We don't always agree with each other, but at least people expressed their views politely and did not resort to nasty online fights like those you see on other social media."
The app's popularity took off across Asia this past week after Tesla founder Elon Musk made his debut on the platform. On Thursday, Clubhouse ranked first in Apple's app store in Japan and Taiwan and it was second in Hong Kong, according to app analytics company Sensor Tower.
Following its launch last March, Clubhouse has taken Silicon Valley by storm, as celebrities and prominent entrepreneurs make appearances on it. In order to join the audio-based app, which is akin in some ways to a radio call-in program, one must receive an invitation from a member.
The app -- currently available only on iOS, but the company says it will begin work soon on an Android version -- had two million users globally as of Jan. 24, its most-recent available figure. The company did not break out users by region, a Clubhouse spokesperson told Nikkei Asia. However, the app has been growing "very quickly" and organically in Asia, from "people inviting people," the spokesperson said.
In late January, the company raised $100 million in funding led by Andreessen Horowitz, a Silicon Valley venture capital company, putting the startup's valuation at $1 billion. With the fresh funding, the company said it will introduce products to help creators monetize their content, including subscriptions, tipping and ticket sales.
Even though the app, which still is in beta mode, is not available in mainland China, users can change the location setting of their Apple App Store to foreign countries in order to use the service.
In a sign of how desperate some Chinese netizens are to have a voice on Clubhouse, invitation codes for the app are now sold at 150 yuan to 400 yuan ($23 to $62) on Taobao, an online marketplace owned by Alibaba Group Holding. On Weibo, a Twitter-like app in China, the hashtag #Clubhouse invite code in the past week topped the trending chart.
So far, China's censors have yet to come after Clubhouse, which has become an enclave for tech enthusiasts, entrepreneurs, scholars and media workers to take part in real-time conversations on a wide variety of topics. Most non-Chinese social-media apps -- including Facebook, Instagram, Twitter and Tinder -- are blocked in the mainland.
"It's fascinating for me to see how people from different sides [of an issue] are so drawn into having interactions with others, and perhaps curious about others' viewpoints," said a Taiwanese businessman working in mainland China who has been captivated by politics-focused chat rooms that include journalists, students and even activists in exile, some with more than 2,000 participants.
"I hope such precious time can last a few more days," the businessman said.
Indeed, the rise of Clubhouse could soon lead to its censorship in mainland China, where authorities already have raised eyebrows over the app's presence.
The state-run Global Times published an article on Wednesday with a headline that said the app would "unlikely be popular in China." It is "nothing creative but similar to Chinese real-time voice service apps such as Lizhi Inc. and YY.com," the article said.
Amid a widely expected ban on the U.S. app, China crypto entrepreneur Justin Sun invested in Two, an audio-focused social app that he called China's Clubhouse. Other Chinese apps that feature similar functions, such as Dizhua, Tiya and Yalla, also have gained popularity.
"I don't think censorship would be a problem for me or most users on the platforms because we are here to talk about tech, startup, venture funding or just gossiping," said Huang, a Chinese engineer working for one of the FAANG -- Facebook, Amazon, Apple, Netflix and Alphabet -- companies in Silicon Valley, who also requested that his full name not be used.
"We are not talking about anything that would be of interest to the Chinese government," Huang said.
Ding Hen, a marketing manager in Shanghai, said a possible ban would not stop Clubhouse's tech-savvy users from using the app. "I think most users of this app in China know how to use a VPN," he said, referring to virtual private networks that are designed to mask internet usage.
"For me, the main appeal of the app is not talking freely without government censorship, it's the opportunity to connect with interesting people across the globe," Ding said. "Even celebrities like Elon Musk!"
Additional reporting by Yifan Yu in Palo Alto, U.S.