The challenge of Google+ and entering my circle of trust

I recently signed up for Google+ and in typical Google style its somewhat spartan in style and instruction on how to use it.  I'm slowly stumbling around trying to figure the system out.

There are some improvements over Facebook in my opinion, most specifically the 'circle' system where you can place individuals in multiple different groups so as to filter and direct your comments, pictures and information to specific groups.

Even if Google+ is 'superior', will it eventually exceed Facebook in popularity?  Not necessarily.  Part of the challenge Google+ faces is the size of their network is MUCH smaller than Facebook's (which is currently over 750 million people!) Network size is very critical as a social network with very few 'nodes' provides a much lower utility even if it's 'better'  [See Metcalfe's law]  Google+'s strategy of slowly rolling out the system via invites from current members mitigates this problem as people are automatically creating more connected 'nodes' in the network instead of random additions you don't personally know.

Right now my plan is to use Google+ as a social media outpost/gateway for my twitter and virtual friends versus Facebook for my 'in the flesh'  friends.  It will be curious to see how the two competing social media platforms evolve.

Many thanks to downtown Josh Brown for being the first person to put me in one of his circles.  Hopefully I'm not in the deranged fanboy category but in the circle of trust...