There are several ways you can monetize your proxy.
It's is generally agreed that Adsense is best for the landing page, but as we all know we cannot put Adsense on the proxified pages ...
Besides a banner or a rectangle ad on the proxified page, such as from Adbrite for example, a few popunders can be a nice complementary source of income.
My traffic is such that I cannot join Adversal, because less than 50% of my proxy traffic is from the US. As a result of that I have been looking for another good ad network which has popunders at a decent rate.
I have found Popads.net and tested the additional source of income for proxies for two weeks.
Results are above expectations, response time from account manager superb, and the minimum withdrawal is only $5.00 for PayPal and AlertPay!