There’s one question your hear a lot in the international marketing/SEO sphere recently: Can and will Google+ grow enough to catch Facebook someday?
The situation here in Japan is a little different. Gree, Mixi and Mobage are the leading social networks and Facebook, although progressively gaining ground, is still fairly far behind the 100% Japanese SNS, that are probably more adapted to the local audience.
Another point is, Google+’s growth in the West owes much to the search engine itself, and Google’s very aggressive marketing. But here in Japan, Yahoo is still the leading search engine, may it be by a small margin, and it won’t display results depending on your circles, or promote G+ directly.
Actually, Japanese SERPs tend to give Google+ much less visual importance when compared to their European/North American counterparts. It doesn’t necessarily mean Big G isn’t trying to break into the Japanese market, but they are most like aware of the uniqueness of this market and may not want to spend too much money.
Does it mean Google+ shouldn’t matter for Japanese businesses? Not at all! As a rather niche SNS, G+ in Japan will attract techies, other marketers and in general people who are active on the Internet. I can still offer some interesting opportunities, not to mention the potential SEO benefits.
My take would be: see Google+ in Japan a bit like you would see LinkedIn, a place where you can meet interesting people you may want to partner with and increase your B2B efforts, rather than a website where you will be easily able to reach large audiences and the mass market.