Beyond brand-hungry strivers, masses of free laborers—from coders building Linux open-source software to editors fine-tuning an entry on Wikipedia—continue to toil without ever seeing a payday, or even angling for one. Many find compensation in currencies that predate the market economy. These include praise from peers, a respected place within a community, victories in online contests, and satisfaction from helping others.
This is a really fascinating topic for me, people's motivation on the internet which is often not tied to monetary compensation. In fact, depending on the exact situation (as the article notes) money would upset the relationship. It does get much harder when the site itself -- unlike Wikipedia or open source projects -- is directly trying to make money.