I've dealt with pbmining in the past and I have to say it is legit and run by a stand up guy. Basically all he does is successfully predict future winners more often than most and splits the profit between all hash holders. If he didn;t have such a long and prosperous track record, I'd say it was all luck but in this case it seems more like a guy that really understands the game. From personal experience I can say with all honesty that I have no complaints about pbmining and have always been impressed by their service.