$2.00 CPM for as long as pop-unders window ...

http://www.adpowerzone.com/
$2.00 CPM for as long as pop-unders window remains open for at least 20 seconds. 1 pop-under per hour. Often pop-ups are multiple. Payments are issued NET30 after the minimum payment threshold of $50. Not recommended.

這個我也沒做過，信譽不知道。