idev is a great program. Used it for many years. When we swapped to WHMCS, we used the internal affilate system.
Affiliate programs do work, if marketed correctly. There are companies that give 500% payouts, and there are others that give 10% recurring monthly payouts. I've always found that our customers enjoy the recurring money rather than the quick payout.
Of course, getting 500% payout on a $179 dedicated server is a great promotion - but very few businesses can support such a hole in the pocket! 10% recurring is easier to swallow.