I agree with everything written in the '#spam' post, though I'd like to revisit the last line here since it's more to the point of this discussion.
I think promotion should he used to include people who have shown they are outstanding community members. Regular old community members can get in the door with a minimal amount of conversational engagement.
The intent of this discussion (at least, how I'd like to view it) boils down to the retention rate of new users post-promotion implementation. Outstanding community members of late, to me have arisen from their own posts, sometimes taking 5 posts or more until interest (shares) come. That is, once they've gotten comfortable with the community. I would be surprised if that was after they've completed a full spoke.