Amazon will also almost always ship their product within a day. I can almost always order something with my Prime membership Monday and have it on Wednesday with no extra shipping costs[1]. The 3rd party? Who knows. It might take them a day or two to ship. Or more.

[1] Ignoring the $75 annual fee for Prime, of course.

Yes there's definitely the prime vs non prime vs 3rd party price differences.

But are you sure there's no evidence of what he references? He seems pretty explicit, and it seems a very odd conclusion w/no specific evidence: "prices on offer to different customers varying for the same product, presumably on the basis of the customer's willingness to pay more for goods in prior transactions."

Here are the two examples of it coming up that I remember, both due to Prime vs. non-Prime and Amazon switching the first result to a lower priced third-party: http://crookedtimber.org/2008/12/22/amazons-price-discrimina... http://brightviolet.wordpress.com/2010/05/18/amazon-coms-pri...

Maybe someone has a real example though... I just remember the debunked ones.

When I hear an odd conclusion with no evidence, I usually disregard the conclusion, not infer the existence of fascinating undetected evidence.

When I read an article linked from Hacker News, then read some comments that are generally not tearing it to pieces, I assume the author must have some credibility and therefore is not throwing out conclusions for fun. Also, I have a minor in inferring existence of fascinating undetected evidence.