The Chinese online blockbuster drama Day and Night, which Netflix bought recently - its first purchase of a Chinese internet drama - is emblematic of the changes that are now underway.

Made and released by videostreaming service Youku, which is owned by the internet giant Alibaba, the 32-episode detective drama centers on the twin brothers' efforts to clear the younger of the two on charges of murdering a family of five.

Since it debuted online on Aug 30 it has been viewed more than 4.5 billion times, Youku says. On China's most popular review site, douban.com, the drama racked up a score of up to 9 out of 10, while the Amazon-affiliated IMDb gave it 8.9 points out of 10.

One critic on IMDb called it "the Asian version of Sherlock Holmes with a shocking twist and turn". "With a tense and an absorbing plot, along with the superb performances the actors give, this drama is certainly a pleasure to watch."

Netflix plans to make the series available in its global market of 190-plus countries and regions. Xu Zhimin, assistant president of Youku, says the purchase is "an uplifting signal" for Chinese content makers.

"The quality of Chinese dramas has risen greatly over the past five years, and as a result they have won recognition in the international market."