Michael,

You're right, very similar, the reason for tons of other social networking sites to become Niche specific...

And one of the reasons why Niche social bookmarking is so popular these days as a marketing tool...

As far as I know Myspace was originally setup for Musicians and Artsy related stuff...

But like with everything, things change...

Might give you a few more perspectives...
http://www.google.com/search?hl=en&c...Se arch&meta=

Phil