I wouldn't be so quick to disagree.

I spent 2 years generating over $1mil a year in sales through the Amazon affiliate program - to be dropped without warning or contact. No amount of follow up and attempts to contact my, previously very accessible, account rep resulted in anything. Not even an explanation on why my account was closed, outside of being told that I could take legal action (in the state of Washington) against Amazon to collect on the nearly $40k in yet-to-be-paid earnings.

I disagreed that it 'would be a waste of their time'; not saying they'd act rationally. In my limited experience it seems like they don't.

- (business lost to other sites with lowest price)

it's entirely possible Amazon did this math

Where did you get $50K from? I would guess that's a huge factor above what they exactly make. I'd estimate somewhere a few thousand (and maybe even less than $1000 some months) to $10K at most. If they're making $50K/month, they must be very very good marketers, or they're doing something very shady.

I said "transaction volume", which is the value of what people paid Amazon via PZ's affiliate links, not what PZ made in affiliate fees.