charlly008: even though I generally don't agree with the original poster, your reasoning seems kind of weird. the more social sites there are and the more social sites everyone are part of, the less attention they give to any type of advertising/social spam.
There are many invitations, but you have to judge in which you can reach more people. So do that according to your needs.
I suppose it's not really useless if a certain demographic finds each particular site entertaining. For those of us using the most popular networks, yep...the consistent popping up of new networks seems like overkill. But then again, if you're a business owner then there are ways to leverage these new avenues for inbound marketing and social signals for your site, which the search engines reward with better ranking.
I'm agree, They are acting like spammer, until we have to live any new inventions but still social networking like facebook, twitter doing great.
What qualifies as a social site? I mean it's the year 2012 and social interaction on any site is important, the goal is to make visitors members feel apart of your site... and you do this with social aspects like discussion, chat, comment ranking, simple user profiles, ratings, content submissions etc. etc. So this thread is far to open and vague to really comment - only the O.P really knows what he means - I am guessing that he means "Facebook clones", "Twitter clones" etc...
I think there are far too many social sites around these days, for example Google Plus really hasn't taken off, why? Because there are loads of other social sites, all act in pretty much an identical way!
Nah it hasn't taken off - just a lazy: 195 million members... shit I mean who would be happy with that!? Google+ is new, Facebook took years to accomplish those number... It took Facebook 4 years to hit 60 million members... Google+ isn't even a year old yet... so give it time. http://mashable.com/2012/01/03/google-growth-2012/