As the conclusion of this series, dare I say that we still do not have a very successful local (generic or vertical) SNS at this moment. But we do have decent special purpose SNS, like Blinklist, Nuffnang and Adverlets, as posted here.

Here, I would like to summarize three key success criteria of SNS:

• Marketing strategies - viral marketing, SEO and various online and offline marketing.
• Elegance of the service - localized, "killer app" to encourage return visits, first to market etc.
• MONETIZATION - advertisements, affiliate programs, subscription, revenue-share on mobile service etc.

• Crowd pulling and retention.
• Multi-racial community.
• Local micro payment infrastructure.
• MONETIZATION.