In some cases the contributors just want to contribute (whatever it is, code, help, research, etc) and the people running the sites, even if they are making āa profitā give the contributors that chance. I think the social networking sites can be very revealing of the other sites as well. We do social networking for entertainment, and itās free, so we really shouldnāt have a problem. We are having fun even if we are generating inordinate amounts of money for someone else at the same time. If you contribute to wikipedia, you are doing it because you are getting some benefit from it as well. Anyone who is doing coding for community projects is happy that they exist - itās much more satisfying that doing personal projects that no one will ever see and you wonāt ever think about again.
I agree that it would be better to be your own boss, but itās not always practical.