Well since I (Cloud 9 CAsh
http://www.cloud9cash.com ) have offered 80% payout promotions in the past I'll shed a little light on it
I did it to get new affiliates and would only offer it for a month (February only 28-29 days) in years past
The key having your own traffic. Expenses are in place for hosting, content, customer service and so on. Those obligations have to be met anyway
For discussions sake let's say I pay 13% for processing and have a 5% holdback. That leaves me operating on a 1% profit margin. My expenses are already incurred so doing a 80% payout is fine short term to get more affiliates
This year I am considering something entirely different for a February promotion ..........
...... $24 PPS
Plus once members are in there are ways to additionally monetize ;-)
and traffic can always make money, if you find the right combination