I wrote a post recently discussing Social Influence titled "How To Become Influential" which talks more about how networks will represent What You Do and Who You Are, not how much you can game the system. Games are fun, but should only be used to build the experience, not the content.
For a bit of fun, I recently joined Empire Avenue (Ticker: LAWS). It's a place to buy and sell people (in a virtual stock market currency) and essentially own a piece of their social net-worth. While people may laugh at the idea, it's a brilliant concept and the idea that we should value each connection is very important. More importantly, it's a great way to find new people to engage with.
The system can be gamed (one of the easiest ways is to buy someone famous as soon as they sign up) but as the game fades (or becomes the background focus) what will happen to the spam artists or people exchanging purchases?
With any network you should remember to keep engaging, connecting and being real - so if the game fades around you, your connections will continue to grow.