I think the utility of fb as you describe it is easy to replicate regardless of your social network structure. However, it is difficult to get past the enormous

I think the utility of fb as you describe it is easy to replicate regardless of your social network structure. However, it is difficult to get past the enormous network effect advantage that existing social networks already have. Fb and twitter logos abound in any sports or news broadcast. That’s the hurdle for any up-and-coming social network.