I agree that this is pretty much cookie stuffing, but calling it a "tax" seems to imply that this cost is passed on to the user, when it is (as the article mentions) actually a cost born by Amazon.

True not the best wording. Was thinking about it more from the perspective of Reddit taxing Amazon.

If I were Amazon I'd be disappointed not because of the poor quality traffic, but because a top 100 site, with threads on every conceivable topic, can't successfully promote a site with products in thousands of verticals.