A still from South Korean TV series Descendants of the Sun.[File photo]

Descendants of the Sun

is not the first drama to bring a sharp rise in paying viewers. Last July, the Chinese series Grave Robbers' Chronicles, based on a best-selling series of young-adult novels, attracted 1 million new VIP members to iQiyi. In that case, VIPs were allowed immediate access to all episodes, rather than the regular updates provided to free users.

Other online players, such as LeTV and Youku, have begun to offer a range VIP memberships alongside their free services. At Youku, for example, free users can watch the first two episodes of Yong Pal, another popular Korean TV series, but only VIP users can watch the remaining 16. LeTV allowed free users to watch the whole of its latest cliffhanger drama, except the final installment, which was only available to those prepared to pay.

According to last year's white paper on individual paying members of online streams in China by consulting firm iResearch, the China Internet Network Information Center and iQiyi, the number of people prepared to pay up front for what they watch is rising steeply, described in the paper as "the beginning of a new era" in China's viewing habits. The amount paid for such services has jumped from 210 million yuan in 2014 to 590 million in 2015.

"We took four years to find the first 5 million VIP users, but only five and half months to see another 5 million," said Zhang.

Yin Hong, director of the center for film and television at Tsinghua University, said the changes to the membership market reflected a greater emphasis in China on protection of intellectual property rights.

"Paying to view adds value to the value of the intellectual property and the member gets higher quality video sources, It really is a win-win situation," he said. Online stream providers are now competing fiercely for exclusive rights to mainstream TV drama.

While some drama-addicts are happy to pay for their high quality fix, many are looking for loopholes. In some cases, multiple users may share one common VIP account and so selling ID codes and passwords online has become widespread. These kind of transactions are currently a gray legislative area. If the win-win expansion of TV is to continue, Yin believes the government must act to better protect the interests of IPR holders.