The success of The Iron Lady in Australia means it will be rolled out onto another 30 screens in the next few weeks, starting from today.

The personal/political drama about former British Prime Minister Maggie Thatcher grossed $6.1m (A$5.92m) from 116 screens in its first 17 days in cinemas, a result that Icon’s Australian head, Greg Denning, is “ecstatic” about.

He expects a final gross of more than $10.3m (A$10m), which is regarded as the equivalent of a film taking $100m in the US. Pro rata, the film is doing even better in New Zealand.

“The film is proving to be the clear-cut choice for older upmarket audiences … not enough films are made for empty-nesters,” said Denning. The anecdotal evidence was that audiences were broad, however, in part because of Meryl Streep’s presence.

The Iron Lady was treated as a broad, mainstream film in the marketing campaign, with “a sizeable budget” spent on radio, television and outdoor. There was some access to Streep, Jim Broadbent and the director for publicity purposes.

A second burst of television advertising will occur next week; vox pops of happy cinemagoers were used, a technique not often used in Australia.

The film launched on December 26 — Boxing Day — one of the most lucrative days of the year in cinemas.

“Our opening week, taking into account screen numbers in both territories, was on a par with the UK , which is terrific and shows our audiences really do succumb to UK films, maybe more than any other territory,” said Denning.

The Iron Lady’s performance is a textbook example of a successful platform release, despite it being a model that has lost favour in recent years because of the highly competitive environment. Platform releases favour older audiences because they don’t rush to see films.

Icon deliberately held screen numbers down at first and, to plan, cinemas were crowded and the box-office charts showed a very high screen average — $23.12m (A$22.44m) in the first 10 days compared to $20m (A$19.41m) for Fox’s January 1 release Alvin And The Chipmunks: Chipwrecked, on 265 screens, and $14.82m (A$14.38) for Universal’s boxing day release Tower Heist on 252 screens.

Regional cinemas will especially benefit from the 30-screen expansion; generally these cinemas don’t have many screens left over by the time they’ve programmed blockbusters.

Three films were released on boxing day on more than 400 screens: Roadshow’s locally-made animation Happy Feet 2 (463 screens), which has grossed $8.53m (A$8.28m) in the 17 days since; Paramount’s The Adventures of Tintin (448 screens), now at $12.48m (A$12.12m); and Fox’s We Bought A Zoo (400 screens), now at $6.26m (A$6.08m), which has held on to only 235 screens, saying much about its disappointing performance.

On 275 screens was Walt Disney’s War Horse, which has grossed $7.82m (A$7.59m). Tower Heist has grossed $8.29 (A$8.05m) and has, impressively, risen from 218 to 253 screens. Albert Nobbs and The Skin I Live In also released on Boxing Day and, on less than 30 screens, have grossed less than $515,000 (A$500,000).

“The Australian marketplace is always a solid performer with British drama but the popularity of Meryl Street in this role has exceeded our expectations,” said Denning’s boss Mark Gooder from LA. “Who would have thought Margaret Thatcher would prove more popular than The Queen?”