Following the discussion on Referral Programs I started looking for ways to make it automatic and also use a percentage like so many recommended.
The only complete free system I found was JAM. It took a few tries to download it on the server (I made a mistake so tried manually moving all the files to the correct folder but then forgot that the install.php was deleted and then took another hour to delete everything and set it up again). However I am unable to understand the principle of it. Let me explain. I don't have a clue how the affiliate system will know when a sale is complete? I can redirect to any page I want. But it won't mean that the sale is complete. I use Client Exec. The JAM documentation said that I only had to enter the values it asked and that I would be prompted to fill out a few more options, but it does not! It seems set up but I tested it and nothing happened.
I know this is not a forum about JAM support, just wondering if anyone else as used it with success. This is the link to it, there is a how to guide and an extensive documentation but maybe I am not looking at the right place. http://jam.jrox.com/