Is there a precedent you're referring to? Because I believe all of the above social networks started as... social networks.

"Innovator's Dilemma" describes a similar process. An underdog comes along, creates an inferior product or a product addressing slightly different needs, and then slowly but surely builds up its feature set to address the big dog's other customers.

Again, where's the precedent in the world of social networking...

What does it matter?

I thought Facebook stared as as a hot or not clone for Harvard students.

That was zucks facemash website.