Dan Marotta advocates for adding game mechanics to online communities:
"By making things competitive, you encourage members to engage in the desired behaviors and goals of your online community that would otherwise seem dull and unfulfilled."
I disagree. It's dumb to gamify community activities. It's the equivalent of people dashing around your neighborhood with a scorecard. They run from person to person, exchanging a few sentences collecting points for each exchange.
A related, but more useful concept, is the reputation system. Reputation systems benefit the entire community, not just the individual. Reputation systems help establish a social order. Reputation systems encourage members to engage in behaviours that will increase their reputation. These rank quality above quantity. Reputation systems let users know whose answers carry the most weight.
Whilst game mechanics focus on gamifying the community thus making it both more addictive and competitive. A reputation system is a long-term effort to build and showcase your reputation to a community – both of which are positive to the community as a whole.
You can find different types of reputation systems here.