WHEN Matt Corby and Natalie Gauci take to the steps of the Sydney Opera House tomorrow night, they will be waging a battle beyond who will win the reality singing contest.

Their face-off represents a paradox which has plagued Channel 10's Australian Idol franchise since its 2003 inception - are the male contestants more marketable than their female counterparts?

Idol judge Mark Holden is the first to admit the judges had hand-picked Corby from the beginning as an easily marketable manufactured star.

"Matt we hoped and expected to get there (to the Idol grand final)," Holden told The Advertiser.

"Matt has all the credentials to have a really great career and be around long after Idol becomes a footnote to television history."

Holden admits it is possible the judges have gone easy on Corby to ensure he is in the final mix.

"Perhaps we have, we may well have," he said.

History - and record sales - are witness that the males of Idol have made more of an impact on the Australian music industry.

Australian Idol signing label Sony BMG appears to have had little trouble boosting the record sales of inaugural winner Guy Sebastian, his runner-up Shannon Noll and most recent winner Damien Leith. 2004 runner-up Anthony Callea claimed the highest-selling Australian single while Casey Donovan - by whom he was defeated - has faded into obscurity.

To bolster the female fortunes of Idol, Sony BMG then thought up the Young Divas - which originally comprised one-time Idols Kate DeAurago, Emily Williams, Paulini Curuenavuli and Ricki-Lee Coulter - a manufactured group belting out disco covers in the hope of making some quick sales.

Coulter, who has since flown the Divas coop to be replaced by last year's Australian Idol runner-up Jessica Mauboy, has returned to original and independent signing label Shock Records and is currently considered the most successful solo female Idol on the circuit.

While it is an achievement on her part, her gold status debut album and yet to be tested new album pale in comparison to Sebastian's three albums selling platinum or better and his slated-for-success Memphis-inspired fourth album.

Shock Records chairman David Williams says that for the independent label, genre, not gender, influences marketing thrust.

"There's not a difference between how we market male or female artists, though pop acts are promoted differently to rock or dance artists,"

he said.

Mr Williams said that Shock's partnership with Ricki-Lee was a matter of timing and talent.

"As an independent record label we've been able to give Ricki-Lee the time and support she needs in writing and recording her music," he said.