Really Beyonce it's actually a tie between Britney and Christina! But I voted for Xtina since she has MLJ owning any Britney songs for the past 6 years
2006: Ain't No Other Man - #6 (Gold)
2006: Hurt - #9 (Gold)
2006: Candyman - #2 (Platinum)
All these three songs are from 2006-2007. The digital era impact overseas (and in the US as well) was just beginning. Below is a list of some of the biggest hits in Australia back in 2006-2007.
2006: Hips Don't Lie - #1 (Platinum)
2006: SexyBack - #1 (Platinum)
2006: Promiscuous - #2 (Platinum)
2006: Irrepleaceable - #1 (Platinum)
2007: Umbrella - #1 (Platinum)
2007: Say it Right - #2 (Platinum)
2007: Gimme More - #3 (Gold)
2007: Piece Of Me - #6 (Platinum)
See my point?
And you're saying it like Christina has had 8 flop singles during the digital era in Australia. I guess you went to Christina's discography page and saw her last digital releases, which is very lame. Inform yourself first.
She has had six digital singles in the country.
Three of them (Ain't No Other Man, Hurt and Candyman) did very well for their time of release. Only Keeps Gettin' Better, You Lost Me and Not Myself Tonight (which reached Gold Status, btw) underperformed.
Oh Mother was an European radio single (not released in Australia).
Slow Down Baby and I Hate Boys were both promotional singles (radio singles).
Woohoo didn't even get radio airplay in the country, it was just released for download when you pre-purchased Bionic.
Digital era started in 2005. And she did have 8 flop singles. I went to ARIA database. So my facts are correct. She shouldn't even be in this race.