If you refer through Commission Junction, HostGator waits 60 - 90 days to give you credit for the sale. If the customer cancels within the first 60 days, then you do not get credit or commission. Also, they shave like crazy. I ran a test and had 7 people I know make a purchase and send me the receipt. Out of the 7 sales (4 were prepaid), I received credit for only 1.
I have all but given up on promoting hosting. If you look at the payouts they offer and what they charge for a 1 year contract, you will find out why they do not pay. HostGator can not pay $100 on every $119.40 sale (1 year prepay of baby) and stay in business.