At Search Engine Watch Forums, Discovery talks about how numerous competitors and clients are clicking way too much on PPC ads. The costs are running up and it seems that there's no end in sight. Discovery wonders if there will be an end to PPC as we know it since there are no huge safeguards to prevent costs from going into the negatives.
It's a question to which forum members don't really know the answer. If nothing at all, it's something you need to look at when you analyze your campaigns. You should check if the ad spend is too substantial and are not receiving conversions. You should consider contacting those who are click-happy or by excluding those who do.
Forum discussion continues at Search Engine Watch Forums.