HasOffers is helping non-profit organization, SeeYourImpact, build their affiliate program on a pro bono basis.
The affiliate program is focused on referring new donors to SeeYourImpact.org.
SeeYourImpact.org is a a micro-giving platform for global 501c(3)s.
I am not sure if other networks provide similar offers to non-profits, but the arrangement from HasOffers is the first I’ve seen.
More details at http://www.hasoffers.com/news/affiliate-network-for-non-profit-seeyourimpact.