I received the $25US credit when I got my nexus 7. I now only have $0.34 of this left. By having a $US balance I was able to connect to the US with a vpn connection on my PC and download the daily free music track without the need to register a US credit card.
I have been doing this daily for about 4 months. In the past couple of weeks I have noticed that when I go to the play store without the VPN i have full access to Music, movies etc. This is also the case on my android devices.
If I log out of my google account and go back to the play store I only get the NZ apps only version.
By the looks of it as I was connecting to the store via the US for so long it has defaulted?
Does this happen to anyone else?