12 Feb 2026 · Attribution

Why last-click still misleads install teams

Last-click survives in app analytics because it produces a single owner and a screenshot that fits a slide. Campaign-to-install attribution is not a screenshot problem. It is a claim problem: which exposure, if any, may take the install without inventing a story about the user.

In a typical Bangkok grocery or delivery catalog, a person may see a video impression in the evening, ignore it, search the brand name the next morning, and open the app after a LINE reminder two days later. A last-click rule will hand the install to whichever click happened to be closest to first open. That click might be a brand query you would have received anyway. It might be a remarketing tap that only existed because an earlier paid impression did the introducing. Last-click cannot tell those apart. It only knows recency.

What last-click hides

View-through credit is the usual casualty. Teams disable it to “keep things clean,” then congratulate search for installs that followed heavy video spend. The opposite mistake is also common: a long view-through lookback on cheap inventory claims almost every open in the city. Neither extreme is a measurement strategy. Both are ways to avoid writing down a shared rule.

Delayed opens after store redirects are another casualty. Android-heavy catalogs in Thailand often show a gap between click and first open that last-click still treats as a straight line. If the click identifier expired, or if a second network inserted a click in the gap, last-click will look decisive and still be wrong.

A better owner rule is boring

Vault Nodecore asks students to name three things on paper before they defend a CPI: the lookback they are using, whether impressions may share credit, and what they will call an install that matches nothing. That last label — unknown — is the one last-click teams avoid. Unknown is not a failure of marketing. It is a failure of the matching rule to find a surviving identifier. Pretending those opens belong to “brand” just so the pie chart sums to 100% is how finance loses trust.

If you need a starting discipline, take one week of exports and redraw ownership twice: once with last-click only, once with your actual MMP settings written in the margin. The difference is the conversation you should have been having. The intensive spends a full module on that redraw. This note is only the warning: last-click is not conservative. It is incomplete, and incompleteness dressed as simplicity still misleads install teams.