I'm working on a site to sell many of my scripts and I'm writing the affiliate system. And I started day dreaming. It was like Paypal added two new fields inside the HTML payment forms that were named:

partner_share=Number|Percentage & partner_business=paypal_email

And this way Paypal could automatically share profits for my sales and, in case of financial disputes, they could handle the chargebacks too withdrawing amounts from both accounts. I understand this would be a PITA for them but it would be sooooo cool and make life sooooo easy.

PS: If this is possible in Paypal right now do slap me with your knowledge.

PPS: Adaptive payments come close to my dream yet miss it by lack of chargeback handling and multi-target withdrawl on behalf of Paypal.

PPPS: Some more reading on the subject from Tim Nash. Has some pretty drawings :)