Amazon's Kindle devices are selling in China because the e-reader allows users to log on to banned sites such as Twitter and Facebook, reports say.
The device bypasses the infamous Great Firewall, making it popular on the so-called grey market according to the South China Morning Post.
Officially the Kindle is not available in mainland China.
But a quick search of Chinese auction site Taobao reveals hundreds of them on offer.
The device sells for between 1200 (£112) and 3500 (£327) yuan.
Chinese bloggers told the paper they were surprised to get access to sites banned by the Chinese authorities.
"I still can't believe it. I casually tried getting to Twitter and what a surprise, I got there,"
"And then I quickly tried Facebook, and it perfectly presented itself. Am I dreaming? No, I pinched myself and it hurt," one blogger said.
Kindle software is primarily designed to allow users access to e-books and other digital media but also allows for web browsing.
Professor Lawrence Yeung Kwan of the University of Hong Kong's Electrical and Electronic Engineering department told BBC News that he was aware of people on the mainland using the Kindle to log on to banned sites.
He thinks that Amazon is likely to have a 3G partner in China.
"The Kindle software routes traffic directly to Amazon's servers," he said.
But it would not be a difficult job to stop it.
"If this doesn't have encryption the authorities just need to turn on the firewall to stop it but if there is encryption the government would have to talk to the carriers and order them to stop forwarding traffic without access to the encryption keys," he said.
He thinks use of Kindles to bypass the firewall is unlikely to be widespread.
"The Chinese government could easily block it and maybe the reason they haven't is because the device currently isn't available in China officially and there are no Chinese language books so people aren't that interested," he said.
There are ways for Chinese citizens to dodge the censors although none are automatic, in the way the Kindle is.
Some use free, open source, peer-to-peer software such as Tor to evade the censors although some estimates suggest only a minority of people use such technology.
But more people are realising that content is censored and looking at ways to bypass it.
"Ordinary people have found ways to scale the firewall and it is almost impossible to stop," said Professor Yeung Kwan.
Amazon did not offer comment on the story.