Referral Codes to Track Referer Bookings and Reward Referrer

Would it be possible to set up a feature to create referral codes that can be tagged to the site's URL so that we can track bookings made by guests who have been directed our way by special referrers and reward our referrers accordingly?

You could perhaps set this up similar to the coupon system giving us the option of offering a discount and/or something extra like a free massage or a free night stay or something extra for the guests who are referred to us with one of these specific referral codes.