A retailer magazine has noted that Amazon Australia was one of the fastest growing retailers in the last few months... thanks to the GST embargo by Amazon America forcing Australians to shop at the Australian site (before July, Amazon Australia was struggling, because the range was crap, and we would just buy the cheaper items from Amazon America).
With the reversal of that decision starting in a couple of hours, it will severely impact on the sales of Australian items on Amazon Australia, because people with Prime membership will still buy the cheaper American items (free shipping), and people without Prime membership will just shop at the Amazon America site (as many items available to non-Americans were not listed on Amazon Australia).
Amazon Australia will still be making a lot of money from the Prime memberships... but people like me will probably terminate the subscription if we aren't buying as much through Amazon Australia to make back as much "free shipping". (I subscribed because I expected to be buying enough American items to add up to a fair bit of free shipping that was more than the cost of my Prime membership... but now it probably won't be the case.)
By the way... also in that retailer magazine, it was noted that following the success of forcing the government into collecting the GST on imports under $1000, the retailer organisations are now focussing on getting import duties collected on imports under $1000 too.... which I think is 5% for toys at the moment.