Layer one, trackable attribution
Give every creator a unique code and a unique link. Codes get shared and screenshotted, which is a feature because it captures spread. Links capture the click-through crowd. Together they give you a floor on performance. A floor is a useful number to negotiate against.
Expect the floor to understate reality by a wide margin. People see a creator post on a phone, forget the code and buy through search two weeks later. That sale shows up as brand search in your analytics with the creator invisible.
Layer two, ask the customer
Add one question at checkout or on the thank you page. Where did you first hear about us, with a free text box or a short list including specific creator names. Response rates of 30% to 60% are normal and the pattern is directionally reliable.
Compare that answer to your platform attribution every month. If 20% of customers say TikTok and your analytics credits TikTok with 4%, you have found the gap between measured and actual. Weight your creator reporting accordingly and say so in the board pack.
Layer three, the holdout
Once a quarter, stop creator activity in one region or one audience for four weeks and watch total revenue, brand search volume and direct traffic. The drop is the real contribution. It is the only method that survives contact with a finance director.
Track brand search volume weekly in Google Search Console alongside it. Creator activity moves branded queries within days. Branded search is one of the cleanest leading indicators that a programme is working before the revenue line catches up.