Though it doesnt make a huge impact in a market like the Japanese one which is very very Japanese, in a country like Australia or even in Europe this can be a huge deal and force retailers to either cut back on future orders with the supplier (and jeopardize the inroads and networks a manufaturer made to get a foot hold in that territory) or may even result in the retailer going straight out of business. So to clamp down on it, retailers agree to not sell outside their territory, and in turn are assured that further competition wont arise unexpectedly from outside their region).