Obviously it depends on the network. If you start making sales on a certain CPA offer, your affiliate manager can bump you up to a higher payment amount. My experience though is that they will start to scrub (withhold leads) when you start making a lot of money. It is B.S. but hard to dispute. If this is the case, move on to another offer. I had one email submit (non-incent) offer that was converting at like 20%, but since I have made over $5,000...the conversions are down to 5%.