These schemes are potentially good as long as they are rewarding quality and not used by cliques. People will delegate anyway if there are rewards to be had. I am sure it is hard to monitor all they vote on, but I hope they have good curators. I sometimes get a Curie vote, but that's rare. You seem to one of those that buildawhale favours, so you do okay.
!BEER
Curie votes are relatively non existent these days. Especially if your account is big. I don't think I would call these schemes but that might just be a language barrier thing between us. Schemes carries a nefarious connotation for me. I do think there needs to me something for those mid level accounts. Plateauing can feel like failure at times.
Call them what you will :) I think if you can guarantee a few dollars per post then you are doing okay. A lot is likely to come from auto votes, so they are probably not even seeing what you do. People need to build a following of those who engage and not rely on curation projects.