Simple But Effective Referral System

Hello, I am looking for a very simple to implement referral system for our website. The referral system should be totally standalone with own database and easy to use for the site user. I am thinking about a system where my current customer can request and have a unique referral link with id sent to them via email or generated on the site in the customer account. I also need a referral link to automatically be sent to every one customer who signs up. After he/she as made a successful referral to a new customer he/she earns a commission each time their code is used at checkout of our site. I want to have them ready as 1, 2 and 3. Easy interface, I need track-able links which is assigned to the referrer. Our site if you want to see how it work is [login to view URL] If you do a dummy order and sign-up you will see how it works. If you have any question please email