While the economy may have something to do with 
the choice of auction sites, I think it's more of 
a name recognition. As you pointed out, Yahoo 
Japan started earlier than eBay Japan, the 
opposite of what took place in America. It is 
important to establish yourself as the leader so 
that you attract a customer base to grow on. This 
is not the only point that matters, but it is a 
major factor in many markets.

---Trebuchet