I'd like to brainstorm with some others on what you think are options for "incentivising" users to use a site in a community. eg. things like user retention, and increasing the odds that people are active on a site.
Other than a point system, what other options are there?
I see this site uses points... but I wonder, does that really help? For instance, I use this site more for the sake of helping others, learning, and thinking... than for the point buildup.
Ask yourself what you're trying to achieve with this. Why would a user want to visit your site? Why would they take the time to contribute? Why would you take the time out of your life and contribute to some other site?
Making people feel like part of a community is the best way to keep them in it. Points are as much a way of recognizing contributors as they are a reward for activity. You can enhance it with leaderboards (monthly, then weekly as the community grows, so the barrier to achieving a spot on it isn't as high), blog posts highlighting the best user-contributed content, and other methods of recognition.
I think the points on this site serve two different purposes. The case you discussed is where people contribute because they want to see their points increase. On this site though I think the points also serve as a feedback mechanism on answers so contributors can see which of their answers are considered valuable and which are not.
Even if you don't like the points mechanism a feedback mechanism is still valuable.
I see the points as a way to quantify doing the activity you enjoy (answering, voting, showing approval, etc.). I enjoy playing basketball and find it more interest when we keep score, but I can't say I like seeing numbers on a scoreboard.
If the nature of your site is more social/collaborative, the number of associations made could drive the points/levels/badges/etc.
This site also awards users with additional capabilities as they use the site more/obtain a higher score.