50% ??? Nah Nah Nah, Britney's worldwise sales are not very far from Goodbyle Lullaby according to mediatraffic and remember Brit had 2 singles already. People think she does ok thanks to USA sales while they often forget Japanese market. May be because their favourtie can't sell their (except Gaga, Backstreetboys and Mariah Carey)
Britney's first week in Japan was around 15.5k-16k and Avril's sixth week there was 15.4k

. And 15.5-16k can consider a decent sales for Brit in Japan
