These have been around a while and have been doing nothing but a selfless service to the website by manually choosing valuable posts and upvoting them anywhere between $5 and $100, depending on if they were democratically nominated, or the level of quality or whatever.
I'm a steemSTEMer, and I can attest to their selfless services. This is what steemit should be all about. Community of people helping each other.
Yeahhh we all rule!