Hydra has a lot of them, but I think they're going the way of the dodo. Somebody correct me if I'm mistaken.
That's what I am finding out. A year or so ago there were tons now I am having trouble finding them.
Another thing I noticed about incentivized offers was, when it came as incentivized or unincentivized the latter paid more. I think the Netflix subscription was offered this way, or was it Blockbuster?