Ok so here is my question. I have several sites with adsense as my primary and only form of monetization. My CTR and ECPM are great but I was looking to squeeze as much money out of these sites as possible. So here is what I am looking for. A script or WP plugin that will popup a window with a CPA add only to those visitors that are leaving my site buy either hitting the back button or closing the window. This popup CPA offer should only show up to individuals who are leaving without making me money and not to those who are looking through the content or clicking through ads or other links. Is this possible?