Amazon's always played hardball with their API (see also Delicious Library mobile). They're like the Oracle of the generally-cuddly API world, but at least they

Amazon's always played hardball with their API (see also Delicious Library mobile). They're like the Oracle of the generally-cuddly API world, but at least they've always been clear and upfront about it. Don't help them to sell things? Bam. By contrast, Twitter's now suffering as it tries to retro-fit a hard-ass approach (though of course with a similar stance from the beginning it's hard to see them getting where they are now).