Best Referral Programs - A curated directory of startup referral programs
KickRef for KickEX - B2C version of a 10-level referral program with many perks
Troopl - Connecting people and companies via the magic of referrals
Viral Loops - Viral Loops is a viral and referral marketing platform to launch ranking competitions, sweepstakes, pre-launch and referral programs.
Referral HQ - Get referrals at Google, Facebook, and other top companies!
ReferralMagic - Turn your users and customers into referral magnets.