I think one solution would be to include an affiliate code, and let the user click a box to donate money back to the recommender after the purchase. That way, the recommender isn't "getting a cut", but is "getting a reward".
Affiliate codes are usually hidden in the URL, though. You don't even notice them unless you're paying attention (though most bloggers, LJers, etc seem to disclaim the referral lest someone else point it out).
why not have code that gives reward/discount to both referrer and recipient?..the example of late pickup is really bad because fines work very well..so do discounts
Yeah. That's what ServerBeach does. They give the sender and the receiver credit. The sender gets more, but the receiver gets a significant $100 off after 3 months.
Don't believe me? Sign up for an awesome (and cheap!) dedicated server account using my affiliate ID: 7XYHDMBU8A
The thing is, I'd recommend ServerBeach regardless of the affiliate program. But some friends might not have signed up without the $100 off, so it's win all around.