I worked at Amazon for several years; one of my team's biggest projects during all those years was expanding certain partner programs to new international locales.
I think Amazon generally prefers to launch quickly in one or two big locales, then expand geographically over time. The alternative is to delay the launch everywhere until support for every region is ready. Launching everywhere at once has its benefits (in particular it can make for better publicity), but potentially at the cost of being later to market and the opportunity cost of revenue not earned during the delay. Amazon has less focus on major PR events than Apple, so it probably weighs these costs and benefits differently.
