You need more than free rocks
We're realizing is that Open Source is more than just free software. Free software is like free rocks. You need rocks, but rocks aren't enough to build a house. You get the Open Source effect only when you have a pyramid of people (roles, actually -- you can still get the Open Source effect if one person fulfills all these roles) associated with the project:
/ Editors \
/ Developers \
/ Contributors \
/ Contributors \