As I was reading your post I started wondering what the position of the people that run the upvote services would be. It seems like flagging those post is kind of undermining their user base. As you said though, I don't think they care as long as the money keeps coming in. It's too bad they couldn't implement some form of manual curation. Groups like SmartSteem at least force you to be approved to a whitelist before you can really start seeing decent ROI.