We have 1 Big Butt site that converts good and retain that would make a great addition to what you have.
http://www.topbucks.com
http://www.bubblebuttsgalore.com
Also, I can have a mobile whitelabel set up for you and specify to use Big Butt content.
Feel free to hit me up on ICQ. All my info is in my sig. This way you can make some $ from any mobile traffic that you get and trust me, you get plenty of it.