Tracking purchases on affiliate sites

[EricPacifico]

I track purchases on one of our sites via Adwords codes. We've just added an affiliate, and I've been advertising in Adwords, to their page on our site. On that page, when the call-to-action link is clicked, it takes the user to their site to make the end purchase. Aside from adding doubleclick (or equivalent code) to the link, Is there a way to track?

Something like including an Adwords code, that I would ask the affiliate to place on their check-out page? If I recall right, I cannot add Google code to a domain I don't have control over.

[RyanKent]

You should be able to set up the payment site to refer the user back to your site after completing the transaction. The "success" page can be used to track results.

[DotCar]

If publisher who you are an affiliate of allows for any custom variable to also be sent with the visitor you can include this and hopefully query it in your reporting from the partner.  This is the case for CJ, Amazon, and eBay but often times private affiliate programs have limited tracking.