I use Wordpress for EVERYTHING! My Adsense sites, squeeze pages, landing pages, sales pages, etc.
The great thing about using Wordpress for CPA is that you can just create one blog on one domain and use it exlusively for your CPA landing pages.
That's how I structure my business. I have one WP site that is all squeeze pages, one that is all landing pages for affiliate markeitng and article marketing, one that is all sales pages, and one that is a blog to showcase all of the MRR products I sell.
It's very organized, and the plug-ins allow you to do just about anything you want in one or two clicks.
Wordpress RULES for internet marketers!