The movie opened in the territory on Sept 4 with a modest five prints which expanded to eight prints before it ended its run on Sept 30, said Mr Lim Teck, chief operating officer of Scorpio East Pictures and co-producer of the film.

Cinema operators normally reduce the number of screens over time as ticket sales shrink, and the rule of thumb for many films is that box office in the second week tends to drop betwen 50 and 80 per cent rather than increase. Rule #1, on the other hand, bucked the trend.

Tong speculated that the snowball growth of screenings was due to good word-of-mouth, 'for which I am immensely grateful'.

Observers have also attributed the growth to good buzz from viewers, critics and bloggers.

Mr Ross Chen, webmaster of leading film site

LoveHKfilm.com, noted in his blog that for a film outside the Top 10 in box-office takings to continue playing for a third week 'is pretty amazing for Hong Kong cinema these days'.

Influential Chinese-language website hongkongfilms.mysinablog.com said Rule #1's long legs and climb in screen count in its second week was unexpected, especially since it had been given so few screens to begin with.

Read the full story in Saturday's edition of The Straits Times' Life!