Mike has written a very informed piece on the expansion of AFL into western Sydney here.
I have the branding prod on my shoulder that shows that I am a Queenslander. However, I grew up in the Blue Mountains. Which means in my regular trips down to Sydney I copped being a 'westie' (and from the sticks) and from the 'westies' I copped worse. Still, as Mike points out football has always been huge in the mts from a participation angle. Although, rugby league was, and is, the game.
Enter the NSW government, who bulldozed a stack of trees and handed $20m to the Blacktown City. Blacktown knew what it wanted to do - build a local sport - and had discussions with Rugby League, AFL, cricket and maybe the FFA. The problem for rugby league is that it doesn't want to expand in NSW - having had Souths forced back on them - and half of Blacktown supports Paramatta and the the other half Penrith. Another team didn't make sense.
For AFL this was ideal. With a major facility in Sydney's mid west it could build fans and launch a major team in 2012.
Blacktown also saw football, rugby union, league and AFL targeting the Gold Coast. These regions have quite similar issues although very different places. Both are growing, Blacktown (17% in 10 years) has over 270,000 people and Gold Coast around 510,000 (fastest growing region in Australia). Both areas have very challenging youth problems that sport and loyalty to a local club can help alleviate. But the Gold Coast has more glamour and property developers willing to back new sporting teams. Now all codes have committed to the coast. The AFL were not quite able to convince an existing Victorian team to move there, and Blacktown had no major code.
Plus Blacktown has a major sporting advantage. It has a large indigenous community. AFL has a long history of making the most of indigenous spirits and talents. Blacktown has already established an AFL indigenous academy. Soon it will have a stadium (the new team will play home games a bit further down the road at Olympic park), a national team that calls it home and the AFL NSW headquarters. Great young players will make all this work.
Cricket have the off-season agreement with Blacktown. Which is a miss for football.
As a footnote, ABC radio is now a more better and less biased source of information on football than SBS. Try here.