If you know Japanese search market a little, you would know Yahoo Japan dominates the Japanese market. It is still true in some sense. Since there is no official and updated market share data for Japanese search engines, I’ve accumulated some of them and concluded it.
As a marketer, all we need to know is the roughly share not precise data. As you can see above, Yahoo Japan is still the largest search engine in Japan. Then, do you need to invest more Yahoo Japan than Google Japan? The answer is No. You need to look at your products and target customers more precisely.
When we decide the amount of investment to those search engines, you better to try both of them. Once you get enough amount of clicks or conversions, the data tells you which is suitable engine for you.
Another tip is that you should keep investing both of them. If one search engine was doing worse than others, there would be some chances to generate orders. In most of the cases, your competitors would do the same thing. Then the heavy CPC competition resume in Japanese market as well. There is more chances at another search engine your performance is not good.
By the way, even though Yahoo Japan uses Google’s platform, the data would not be same. Since Yahoo Japan has a different demographic data from Google Japan. Don’t miss Yahoo Japan even if the UI is not familiar with you..