This is an very interesting point to me, with our start-up we offer the same content in English, German and Japanese. What we found is that, for every US visitor there will be 3 visitors from Germany and 6 from Japan, although 80% of our ads are in English. There simply is no competition in Japan. I don't really know why, but no one writes content online.<p>For example 132 million people speak Japanese.
Only 62 million speak Italian and only 46 million speak Polish.
When you take a look at Wikipedia, Japan has less articles than Italy or Poland.<p>Poland = 708,702 | Italy = 699,426 | Japan = 684,725 <a href="http://meta.wikimedia.org/wiki/List_of_Wikipedia" rel="nofollow">http://meta.wikimedia.org/wiki/List_of_Wikipedia</a>
(I am not aware of any mentionable alternative to Wikipedia in Japan)<p>For everyone creating content online this is quite a paradise, the second biggest economy in the world and the SEO competition is something like it was in the US in 2003.