affiliate tracking techniques

[danger]

hi all

I'm writing my own affiliate software for my dissertation. I'm interested in how the various networks track sales generated by affiliates.

I understand tracking hits from the affiliate side:

1) user clicks on affiliate link which goes to example.com
2) example.com sets a cookie containing the affiliate code, then redirects to the merchant domain.

what I don't get is how sales are tracked and allocated to the affiliate on the merchants side.

One way I can think of is the merchant is required to add some javascript to their sales confirmation page which lets the network know the affiliate code and details of the sale, but what happens if the user has javascript disabled?

another method would be to ping the network (using SOAP or similar) and report the sale that way - is this a viable option?

I'm sure there are variations on the two methods but are there any other major approaches?

[edited by: Receptional at 11:22 am (utc) on Oct. 10, 2005]
[edit reason] examplified URLs [/edit]

[Receptional]

The safest way is to have the sales confirmation page set as the affiliate company's conversion tracking domain. That page then runs the conversion information before directing the buyer to the genuine thankyou page - passing any variables required along wioth it at the same time.

If the thankyou URL has to be on the merchant's site, then a javascript is the most common method, as you surmise.