[Solved]-Django: Implementing a referral program

I have done this a while back and figured my notes could help someone looking for this:

Create referral urls

Whenever you issue a referral url to your user, store it in a table. In my case I had urls for different purposes (‘invite your friends’, ‘share this item’ etc.) So I stored the type of referral as well.
Add an entry point to your site like http://example.com/ref/jklejis to process the incoming url. If you don’t like to have an obvious ‘referral’ url you could use middleware to simply capture a special url parameter on any url to your site and process it that way i.e. http://example.com/items/123?r=jklejis

Track referred visitor

As soon as a visitor visits from a referral I plant a cookie and any further requests by that user are tracked by a piece of middleware that tracks the actions in a table.
I then run a job to parse the ‘action’ table to issue credits to users. I had no real-time requirements here, but if you do then use a signal to specific actions to kick off your code.

I recently came across this project which seems to be still ‘alpha’ but it does something similar and could get you started: https://github.com/pinax/pinax-referrals

You could use a very simple model to keep track of them

class UserReferral(models.Model):
    referrer = models.ForeignKey(User)
    referred = models.ForeignKey(User)

    class Meta:
        unique_together = (('referrer', 'referred'),)

Then you can count how many a user has referred:

UserReferral.objects.filter(referrer=user).count()

Etc..

Keeping track of a user’s session especially after they cross the boundry of signup/login is a tricky issue. I have written a referrals app http://paltman.com/how-to-easily-add-referrals-to-a-website/.