Could this be an added option similar to what tinypass is doing?
From the tinypass website information:
This allows a publisher using Tinypass to split a percentage of specific purchases with another party.
For example, let's say you are a news site and you pay individual writers for their content. You want to pay the writer of a particular article 10% of the sales of their article. You would do the following:
$po = new TPPriceOption("1","1 day");
It's that simple, and we take care of the rest. The writer will receive an email asking them to create a Tinypass account, at which time they will be able to see and track their earnings.