China will ban commercial breaks in sudsers and dramas from next year, a move that could cost broadcasters more than $3 billion a year.

No reason was given for the ban, but it comes as part of a broader crackdown on broadcasting in China, the world’s biggest TV market in viewership terms.

Last month the government introduced limits on the number of gamers, talk shows and reality skeins because they were “too vulgar” and also restricted the length of ad breaks.

“No adverts will be allowed during dramas on any television channel,” Li Jingsheng, head of the TV drama department under China’s State Administration of Radio, Film and Television, told China National Radio.

Sudsers, historical costume skeins and other dramas account for around 70% of ad revenue for TV stations.

“The order is a double-edged sword,” Ren Jianwei, an official of Shanghai’s Drama Channel, told the Shanghai Daily newspaper. “It will certainly affect our ad revenue, but it will also attract more people to watch TV.”

The channel may lengthen slots before and after each episode, Ren said.

As it stands, total advertising time cannot exceed 12 minutes per skein and each commercial break should be less than 90 seconds. However, the frequency of breaks is not regulated and viewers have long complained that there are too many ads in sudsers.