guys seriously - read the original post. He really makes a point that kinda renders his question moot. The higher and the lower payout are backing out at the same ROI. Don't get hung up on the payouts - on zip/email submits or any offer. Different companies are going to have different filters/scrubs and the payouts are going to fluctuate accordingly.
***This is about to get long so stop reading if you might bitch or just bitch and I can call you a douche later.***
Most of the major players in the zip/email submit game are sophisticated enough to measure your traffic individually (if they can't then don't fuck with them - and if you are not direct and the network says they can't then they are either lying or you are not doing enough volume for them to be concerned about). This can be a good thing if you are doing things legit and/or driving quality traffic but is probably the reason a lot of affiliates get scrubbed and pissed at these companies.
If you step back and look at their business model (if you are not familiar try to keep up) not only does your traffic have to back out for the incent company but it also has to be good quality to the advertisers that are on their forms. So your traffic needs to be responsive in their path and wall (noobs - read that as they have to do offers on their path) BUT not only that, they need to be of a high enough quality that the offers that are done back out for those individual advertisers as well.
The reason I make the above statement is b/c if it doesn't back out for the lead gen advertisers and the CPA wall advertisers then they will eventually pull offers or lower prices to the incent advertisers which then they have to pass along to the affiliates. And again, they most likely will track it back to your individual traffic and just either scrub you or cut you off all together. If it is bad enough they will most likely begin to question how you are promoting the offer, which if not compliant, could lead to them not paying you.
One thing for you guys that are NOT working with the bigger incent players direct or at least a major network is that if the above situation happens and the smaller broker/network doesn’t get paid, you most likely will not be getting paid. It is far more likely also that the incent company would hold money from a smaller partner than a larger more established partner. So if you are trying to squeeze a nickel or dime more out of an offer and you decide to go with the latest, greatest ad network no one has ever heard of then you are not managing your risk really well and may Sumit pray to which ever Hindu God that might fall under for you.
One quick last example of how payouts fluctuate and you should really just be concerned how the offer backs out for you. I and my company have been involved in incent marketing for over 8 years now (since they were giving away mailing labels and not iPods/Macbooks) We work with the bigger guys directly and on one particular campaign we run it in 4 different traffic sources. All 4 get a different payout and the second to the lowest is by far our most profitable.