Last-Click Attribution

Last-click attribution is the simplest rule in the book: whatever click came immediately before the conversion gets all the credit. Every touch before it — the awareness video, the first product-page visit, the comparison search — gets nothing. For years this was the industry default, and it's still how many platforms and analytics tools report by default. Its appeal is clarity: there's no math to argue about, and the credited channel is easy to identify. But that simplicity hides a strong bias. Last-click systematically over-credits the channels that sit closest to purchase — branded search, retargeting, and direct — because those are usually the final click. It correspondingly under-credits demand-generating channels like TikTok and YouTube that do the early work but rarely get the closing click. The practical danger: if you optimize budget to last-click winners, you starve the upper-funnel channels that create the demand your bottom-funnel channels later harvest. Last-click tells you who closed the deal, not who created it.