If I was going to host an e-commerce website where I aggregate the products from multiple other websites, I understand one potential approach would be to append some kind of 'affiliate tracking code' query-string parameter to the hyperlink that takes the customer through to the underlying merchant website.
I'm not sure if the 'affiliate tracking code' would get submitted in the final payment gateway request on the merchant website... I'm guessing there's probably more than 1 way to track conversions from affiliate links... Assuming affiliate tracking codes are indeed included in the final payment gateway requests (which I'm not convinced they would be), there's probably no standards about how this works and is more than likely dependent on the underlying platform/implementation.
Where I'm going with all this is I'm trying to work out how affiliate tracking might work for a browser plugin that helps with the conversion.
Interested to hear about some approaches that I could look into?
FWIW I understand I might be able to manipulate the DOM of the e-commerce website as per this SO. This might help, but I'm still not quite sure how the underlying merchant would be able to track this...
TIA.