Filtering the result to year to date 2009, it starting to reveal rather interesting fact.
The overall trend shows that mixi’s gradually losing its popularity, while Facebook is increasing, in Tokyo, Facebook already has surpassed mixi early June, and YTD average shows Facebook is already as strong as mixi. (and if this trend continues, by next month, Facebook will become most popular social network system in Tokyo.)
Tokyo’s shift in trend is unique, as even Okinawa, showing strong MySpace support than rest of Japan, although, mixi is still dominating the popularity there. (I speculate presence of US military base for high support of MySpace in Okinawa.) Okinawa’s overall trend has been following somewhat close to rest of Japan, but perhaps with Facebook and MySpace competing for shares.
Regional comparison for Facebook in major cities in Japan shows that overall popularity volume in Tokyo is much higher than rest of places. (and likewise, comparison with MySpace shows significance of MySpace in Okinawa.
So, it seems like, in Japan, many people are starting to migrate to something other than mixi, perhaps for the fact mixi’s more focus on mobile phone market (and especially, if they use carrier menu to access to mixi from their mobile phone, it won’t show up in Google Insights) as well as more push to Facebook from different sectors (for example, DSi support of photo upload to Facebook.) Somehow, this trend is showing in Tokyo drastically than in different places. This may be mean that there are more international relationship dynamic happening in Tokyo, requires more global communication. (mixi do not allow sign-up without Japanese mobile numbers now)