Hey James,
glad to know the plugin is useful! 🙂

So, we do not have an explicit API for replacing the Adsense module with a different revenue source. What we do provide, however, is a very simple abstraction for adding a new payment criteria (say you’d want to pay per links in a post, or per posts in a given category, or whatever). We have a simple method you can invoke that will have your own payment criteria installed seamlessly. This could easily add you a column in the stats table and integrate it with all the payment features, but you’d still have to draw fetch data from the new source and put them in the database. This we are currently doing with the class ppcp_google_analytics_class.php, where we have a bunch of routines that regularly pull data from Google Analytics and stores them locally in your database. I guess most of this could be recycled for your other platform, but can’t guarantee. I would guess it would require some effort though 🙂

Not sure this helps: do get back for anything more! 🙂

Have a nice day,
Stefano