Myth: switch from last-click to first-click and you'll finally credit the channels that start journeys

Myth: switch from last-click to first-click and you'll finally credit the channels that start journeys

The question: last-click attribution (all credit to the final touch) obviously under-values discovery — so is first-click (all credit to the first touch) the corrective?

What the analysis says: both are single-touch heuristics, and both are wrong in symmetric ways. Last-click systematically over-credits late, high-intent channels (brand search, retargeting). First-click systematically over-credits whatever cheap channel happens to appear earliest — often organic social, a stray display impression, or a coupon site that intercepts already-decided buyers early.

The nuance: first-click has a subtler failure. The 'first' touch you observe is the first one your tracking captured, not the true origin. Offline awareness, word-of-mouth, and pre-cookie exposure are invisible, so first-click hands all the credit to the earliest digitally-trackable event — which can be deep into a journey that started elsewhere. You replace one bias with another and add a tracking-window artifact on top.

Research comparing rule-based models against geo-experiments finds first-click and last-click can disagree by 200%+ on a single channel's value, with neither matching the experimental truth.

Bottom line for practitioners: never 'fix' last-click by flipping to first-click. If you must use a positional heuristic, a position-based curve (e.g., 40/20/40) at least hedges. But the real fix is incrementality testing — no credit rule, forward or reversed, recovers causation from observed paths.