@dustsweeper/dustsweeper-s-faq

That is the FAQ of dustsweeper. It has been around for a pretty long time. You can protect the incoming votes that do not make it to 0.020, and dust sweeper will follow those votes to raise it up to a valuable level which is 0.020, (it kind of comes in at 0.030). In addition if you want to give a vote to someone but you do not have enough vote value they will follow on with a vote to raise your effort to reward someone with a valuable vote.

You do have to buy your vote value, but I felt it was well worth it for me to participate almost from the start. I still try to maintain a balance to help new users that vote on me with no real vote value.

He does a pretty good job of blacklisting those that would try to take advantage of the system.