I just started with this so maybe it turns out I'm completely wrong here... but what I looked for was the following:
*Good project idea
*Enough people intrested in the project
*Good team
*Good bounty manager
*Enough funds distrubuted to bounty hunters
So basicly the same stuff I look for in an ICO except for the bounty part.
Kudos for this Insight of yours. I think you have best summed up the essentials needed to be considered when one desire to really join to any rewarding campaign. With every of these details carefully considered and observed, I think anyone would be on the right track.