Tracking conversion from a portal landing page to multiples domains
I have a portal landing page that reviews different related products. Each products have their own review page that link to a different domain where the sale actually occur. What would be the best way to track conversion in this situation?
Adwords campaign ----> Main portal domain ----> Product A link to ----> domain A ---> conversion page
----> Product B link to ----> domain B ---> conversion page
----> Product C link to ----> domain C ---> conversion page
Is it possible to track conversion this way? If yes, what would be the best way to tackle this?
Thank you for you time.