most programs that i've come across have rules forbiding that
I can't understand why this would be forbidden.
If we were dealing with click through ads, yes, obviously, but for sales, it's a win win situation. You get commission on the sale (equal to discount), plus the 3rd party get their money. All parties happy.
I have dealt with a company who's chairwoman told me they had no business from my 5-6 referrals per day, while employees told me they had contracted 2-3 deals per week. Needless to say, I dropped the company in question like a hot brick.