I just have a very small handful of clips on IS, SS, Pond5, Revostock, and now SXP. IS has been the best for me, but SS has been doing better since they lowered prices a few months ago. SXP hasn't done anything yet. I haved been somewhat pleased with the other two as well, they give me a sale or two a month at 10-20 bucks a pop with only 20 clips or so online.