OT Ad-fail, I've never used their services,
Keith Newton
I wish I had done a screen-grab to share, but only thought after deleting it. This was an Angies List advertisement on my neighborhood list serve for finding good reputable roofers. The ad shows a nice clean cut young man squatting on a shingled roof holding a 8d finish nail about 1/2" from the downhill edge and corner of a shingle with the hammer about to drive the nail down through the top.
Really, If they don't know any more than that about the proper methods of the trade, how meaningful is their claim to send you a good contractor?