One thing that holds true... EVERYBODY SHAVES!
It's not always the network that shaves... The advertiser is going to be the first one that shaves. This is due to changesbacks/retrievals, trial cancels, rebill failures, refund requests, processing fees, gateway fees, etc...
If your traffic is of better quality then you will be shaved less. This is because the more money the advertiser is making on your traffic on the backend the less they "need" to shave you.
It all boils down to the pricepoint the advertiser has set to pay you on the backend. If you are sending quality traffic that doesn't cause chargebacks, cancels, etc... then they are going to shave you less. If you are sending them traffic that has a 50% cancel rate on the rebill and/or they are receiving a lot of CBs/Retrievals on your AffiliateID then they are going to shave you and/or just tell you to stop sending traffic.
Thing is folks... Everybody shaves. Any advertiser that tells you they don't shave is lying... It's the nature of the business. The advertiser isn't going to eat the cost of trial cancels, rebill failures, retrievels/chargebacks, etc... for you. They are in the game to make money - plain and simple.
The network is going to be the last person to shave you... Before you go calling out the network, you are more than likely being shaved by the advertiser.
Cyp