Mike12, I notice you are posting the same info on multiple forums. This is not the place for you to do link building. Beware.
Pop-unders on porn sites are one of the most ingenious guaranteed traffic scam I ever investigated. The way that scam works is the pop-under windows typically pull a random web page from your site, which makes it look like you are getting tons of traffic. Unlike other guaranteed traffic scams, this one is almost impossible to detect because each porn site user has a different IP address. The result is that Analytics or other site statistics shows a large increase in visitors, but the site usually sees zero increase in business. Once a user shuts down his browser for the porn site, he finds all the pop-under windows and just shuts them down.
I personally don't believe that pop-unders on porn site convert well unless you are selling sex toys or memberships for other porn sites.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin