It would be good for both I (as a developer) and RocketGenius. I'd like to encourage my clients to purchase their own single-user license. The best way to do that is to install the plugin for them, use it, and then have them click on the link in their own site to purchase the plugin.
But I am cut out of any earning since I can't include my affiliate link. It would be great if I could set a variable (perhaps as a define in the wp-config?) with my affiliate code. If the client purchases - we both benefit.