I'm working on an e-learning application that uses game dynamics, which include points (like Stack Exchange). There are two aspects to the application that we want to encourage. Actions that benefit you personally, and actions which benefit the community.
In our initial designs we had these aggregated into one points count. In a site like Stack Exchange, all interaction is essentially community interaction so this doesn't present a problem. However, it has become clear that some customers will use the application regularly for their own benefit without ever interacting with the community, while others will primarily interact with the community.
For this reason, we are seriously considering changing to two types of points. One for personal use, and another for actions that benefit the community. Similarly to how many games have gold and mana.
A large part of the reason for this is based on what people use points for. If I am not active in the community but want to compare how I am doing in my learning against a friend who is active in the community, one counter for points just won't work. Hence the competition aspect of having points will suffer.
I'd appreciate feedback on this, whether it is based on experience or understanding, as well as any links to applications / sites which use a dual points system.