If you look at Amazon's
list price requirements there are some incentives there to encourage publishers to price differently in some countries too.
For example, Amazon puts more pressure on publishers to set prices low in the US than it does in the UK by setting the price cap for the 70% royalty option lower in the US ($9.99, or about £6.99) than in UK (£9.99).
So will Amazon get the same level of criticism over geographical discrimination, or is it only bad when Kobo does it?