Impact Radius
Impact Radius is integrated with C3 Metrics.
Affiliate Programs are tagged similar to Paid Search. The C3 tag present on your landing page captures the data from the query string in the destination URL.
The standard tagging for an Affiliate program would be to add the following query string to your click-through destination URL:
This will attribute value across your entire Affiliate program and allow you to discover which affiliate are driving value at the top of the funnel, vs jumping in at the last second.
Impact Radius
To track campaign performance down to the Publisher level, instruct Impact Radius to expose the Publisher ID within the destination URL as the c3nid parameter as follows:
&c3ch=Affiliate&c3nid=Impact-Radius[PUBLISHER ID]
With this data, C3 will match the Publisher ID from a Publisher Report which can be generated from Impact Radius.