Adding to this Thursday night`s Dumb SEO Questions Hangout On Air #49 for +Micah Fisher-Kirshner who said:
I`m on the fence with this. Makes sense to try to prevent spamming, but at the same time, the point of nofollow is such that you`re telling Google not to count it in the first place so your other campaigns won`t affect Google even at scale.
#monopoly