But you're thinking about it backwards. The reason Other has the highest portion of sales is because it's all the odds and ends. If you split it up, you'd realise that it's Europe and then 10 weird regions that produce tiny sales.
Maybe Europe could be split off so we have Americas, Japan, Europe, and Others, but then neither of them would be significant really.
I really like the three region system. Traditionally games have been produced in either the United States or Japan, with a few coming out of France and England. 'Other' is a nice way of examining how impartial observers react to both styles, and because it's so broad they have the numbers to make it seem relevant. Nobody cares if the PS3 sells 92 units in Bangladesh, but they care if it sells 30,000 in Others.
Wii has more 20 million sellers than PS3 has 5 million sellers.
Acolyte of Disruption
