There are also signature campaign which are paying very low and in a month it's not going to be even 40 dollar even for a legendary account. So we can not judge a user based on the criteria of being in a signature campaign. If this is a high paying campaign then the talk is different of course.
I agree which is why I mentioned excluding users who are involved in
decent paying signature campaigns (Campaigns that pay around $50 or higher per week).
Participants from campaigns that pay low amounts as you mentioned deserve to be looked at. Also, I would focus on members from 3rd world countries primarily when compared to members from 1st world countries for obvious reasons.