I see that there are some affiliate networks that use offers from other affiliate networks. For example Axill.com uses offers from Advertising.com and CJ.com. How does Axill.com track the signups? Is there any script already available to track signups on another site?

They have backend systems that communicate with eachother. For you to track signups you'd have to have mutually agreeable software that communicates with their database. I doubt they'd grant you access.

-dk

I always thought it was a bit more simple than that. Surely it's possible to have a script that simply has a 1x1 pixel image you place on the sign up confirmation page. When it's loaded after a signup is confirmed the cookie etc. for that user can be checked and the script can check and see which site this user was sent from (as this would have been recorded when the affiliate link was followed).