To be clear, I'm not talking about trash traffic. Gift card/ stolent CCs, etc are fuckin bullshit. BUT if I'm driving good solid proven traffic, I should be paid for it. Period.
I can't find any excuses right now.. not that the above networks are - but networks are supposed to absorb the risks between the advertisers and affiliates. If you're driving solid traffic and the advertiser skips their bill, we would at least you pay in full and then deal with the crooks legally. Depending on your history with the network and the amount of volume pushed, covering the costs of the traffic bought is another equally reasonable thing to do.