Attribution Models for Influencer Marketing: Beyond Last-Click
Last-click attribution undercounts influencer impact by 40–70%. Here's what to use instead.
If you're judging influencer campaigns on last-click GA4 data, you're systematically underweighting their contribution and over-investing in branded search. Here's the better stack.
Why last-click fails for influencer
Influencer content drives discovery and consideration, not direct response. A viewer sees the post on TikTok, searches your brand on Google a week later, clicks your branded search ad, and converts. Last-click credits Google. The influencer triggered it.
The four models worth using
Position-based. Gives 40% credit to first touch, 40% to last, 20% distributed. Good middle ground.
Time-decay. Recent touches get more credit. Works well when sales cycles are short.
Promo code or unique-link attribution. Direct, simple, but undercounts because most viewers don't use the code.
Post-purchase survey. Cheapest, most useful. "How did you hear about us?" at checkout, with influencer as a structured option.
The blended approach
Layer platform-reported numbers (Meta, TikTok) with promo-code attribution and post-purchase survey. Triangulate. Any single source is wrong; together they're directionally right.
Incrementality is the ground truth
For your top-10% spend campaigns, run geo holdouts or matched-market tests. Expensive, but the only way to actually know.
Need help putting this into practice?
We build operated creator programs for brands serious about creator marketing.