Learn from Wikipedia.
People will work hard even when there’s no money and little credit involved, if the challenge and subject matter moves them.
Thousands of volunteers around the world can keep an encyclopedia up to date and accurate enough to be incredibly useful without a great deal of hierarchy.
All of this can be led with a relatively small team paid for by donations, not advertising or commerce.
The resulting content can lead search results in many categories and become a cornerstone of the web.