e-turnall has a post with a review of Twinity:

Not only is this site modeled to a mature audience, there is functionality for chat, voice chat and a plethora of other great applications.  What a great way to talk with and interact with family if you’re seperated by great distances!

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Twinity, like WOW, did not dissappoint.

and some information about running your own business in Twinity:

What actually caught my eye is that Twinity is looking for people to host some of their communities

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Twinity offers three types of Partner programs. One of these may fit your online business, depending on which aspect suites you best

Give it a read, and maybe get your own business going!