Author Han Han at a promotional event for his directorial debut, The Continent, in Beijing . Jiang Dong / China Daily

As the competition for summer box-office dominance heats up, Wang Kaihao looks at the innovative online marketing techniques being used by domestic film makers.

In recent months a catchy song, A Little Apple, has gone viral in Chinese cyberspace. It has become such a cult hit that it has even inspired square-dancing troupes to mimic its music video. But what its millions of fans did not realize as they bopped along to the catchy tune, is that they were actually taking part in an unusual campaign for a movie that they had probably never heard of.

When Old Boys: The Way of the Dragon, an adventure comedy featuring the song, was released on July 10, the unusual publicity strategy was applauded.

With the song having become an enormous hit, many people who did not plan to watch the film will probably now flock to cinemas out of curiosity.

This summer, many domestic films have fallen short of expectation, and filmmakers have turned to online marketing in an attempt to stay ahead of the competition posed by their more critically acclaimed foreign rivals.

According to statistics from the State Administration of Press, Publication, Radio, Film and Television, the country's overall box-office income in the first half of this year was 13.74 billion yuan ($2.22 billion), including 6.63 billion yuan from domestic films.

In China, there is one month every summer when few Hollywood blockbusters are released so they do not compete with domestic films. This one-month grace period is the best season for Chinese movies to make their bid for box office dominance.