Almost Wikipedia: Eight early encyclopedia projects and the mechanisms of collective action

This excerpt from a dissertation discusses why Wikipedia succeeded when several similar projects failed. The author makes three propositions:

P1: Wikipedia attracted contributors because it was built around a familiar product.
P2: Wikipedia attracted contributors because it offered low barriers to contribution.
P3: Wikipedia attracted contributors because it offered low attribution and low social
ownership of content.

To expand on P3:

In the projects in my sample, ownership over text was often purely social. Several OCEPs whose initiators suggested that textual ownership hindered contribution allowed, from a technical perspective, for at least some direct collaboration on the text. But because they also listed authorship explicitly, a sense of social ownership over text meant this technical possibility was rarely taken advantage of.

He rejects two alternative explanations:

Alternative Explanation 1: Technological Superiority
Alternative Explanation 2: Timing