How to track advertiser & conversion process?

See more:

HTML

PHP

Hi,

I am promoting a tool using website http://www.gopcpro.com. on successful conversion,tool got downloaded from http://gopcpro.com/download.html.
For promotion,i am using various marketing techniques like SEO,PPC,affiliate marketing etc.
I got traffic from all the resources.with some of the publishers,i am paying on CPA(cost per action) basis.now i want to track their action. So now how can i track the downloads corresponding to each resource.

Please suggest best possible solution.
Thanks in advance.
God Bless You.