Open licensing of content

Ownership is an important factor in large-scale collaboration. In small-scale experiments, participants are willing to engage and produce value for a third party. This gifting, particularly when interacting with an active third party (effort creator/maintainer), doesn't extend to large-scale collaboration. Communities, once formed explicitly or implicitly, need a sense of ownership over content.

Projects such as Firefox or Wikipedia are successful in part because the community is free to 'fork' the project they are involved in if they believe in a differing set of decisions. These forked projects don't detract from original (trunk) works, and improvements in one branch often improve other branches regardless of philosophical differences between them.