[SteveEisenberg]

Originally Posted by Little.Egret

Sainsbury's keeps a eye on prices in other supermarkets and gives me a voucher if what I bought from them was cheaper in ASDA.

Does Sainsbury's insist that Mr Kipling can't lower what it charges ASDA, for jam tarts, unless it also lowers the wholesale price Sainsbury's pays?

I don't know what the answer is to my question. But that's the analogous issue. From the OP link:

Competition regulators have taken enforcement action against similar causes. Priceline Group Inc.’s Booking.com settled antitrust probes in France, Sweden and Italy in April by agreeing to drop clauses preventing hotels from offering lower room prices on competing online travel services.

Here is evidence (not proof) that Amazon does what it is accused of:

http://www.selfpublishingadvice.org/...ues-on-amazon/

Amazon’s Terms and Conditions have always stated that authors who publish on other platforms must not price their books lower elsewhere, and authors who do so are in breach. In the past, this rule hasn’t been consistently enforced, but it seems that the policy is being tightened.

Originally Posted by eschwartz

Unfair or not, it is a rather common generic business practice.

Is this meant as a defense of Amazon?