@edsu @adamgreenfield (4) it works best when the newcomer is likely to be engaged, motivated, and trustable: eg, in the post-Sandy situation (as in most post-disaster situations, despite looter myths) new helper almost certainly was not a thief, so high-trust/low-barrier works great.
That’s true of the median open source contributor, but as we’ve learned the hard way the long tail of trolls/black-hats is very long and highly-motivated :( Unclear how to balance that reality with invitationality.