I have to agree with Jo Ann - I think your heart is in the right place but probably not the best method. I think just shopping and supporting a site that treats contributors fairly in itself helps to promote everyone's work.
Yes, exactly. This us-vs-them attitude based on exclusivity status is something that is unique to Istock. It really doesn't fly on other sites. Thank goodness. If you are leaving Istock exclusivity behind, then the divisiveness should be left behind as well. Haven't we all had enough of it by now?
It's great that you want to support hard working artists, but gaming the system at other sites is not the optimal way to show your solidarity.