Datsoup - You just have to sign up. Here's the full list of referral ID's they accept:
If you want to submit your referral link from a program that isn't on the list, you just have to go to Profile and click on "Create referral pool".
Refer-o-matic - Same thing as Datsoup. You submit your referral ID's and wait for the referrals to come. Don't expect to receive hundreds of thousands, but people will sign under you once in a while, which is fair enough given the fact that you don't do anything. Here's their accepted referral list: