Attribution model
Last-click only. The last qualifying ?aff= or ?wm= within cookie life gets credit.
Attribution model
Which click wins the sale. This product version supports last-click only (last_click).
Where to find it
Admin → Settings → Affiliation → Attribution model
Setting key: aff.attribution_model
Admin UI shows Last click (other models are rejected on save).
How it works
The last qualifying ?aff= / ?wm= (or Referer webmaster match) within cookie life overwrites the previous cookie and gets credit at checkout.