I just did an experiment over the last couple of months where I tried out a bunch of different link building services here on BHW and on Fiverr. I tried out around 10 different ones. Two of them gave me good results and the rest pretty much sucked. So now I know which two to use on future campaigns. My question is, should they be done at the same time, or should they be done one after another? One is a high PR blog commenting service and the other is a pyramid link building service.