I am searching for the most efficient way to handle email collection with a referral program. We are developing a web app that will be going live in the next few months. To sum it up I need to: 1. Collect early registration emails on our website. 2. Allow these people to refer friends at the time they register. 3. Send an invitation email to the people who have been referred. 4. Allow registered users to go back and refer more people.
Has anyone seen a solid way of handling this? Mailchimp, etc. doesnt seem to do the trick.