further on the license...check out this out
"Until now ( on license fees ), the commercial networks - Seven, Nine and Ten - have paid the government 9 per cent of their advertising revenue. It is this amount that will be cut - by 33 per cent this year and 50 per cent in 2011.."
So maybe TEN"s license is a lot lower then Seven's because its advertising revenue is a lot lower....
http://education.theage.com.au/cmspage.php?intid=135&intversion=301