What is last click attribution?

Last click attribution gives all the credit for a sale to the last channel the buyer clicked before buying. GA4's version, Paid and organic last click, skips Direct visits unless the whole path was Direct. It is simple and usually fair for one-visit buyers, but on longer journeys it hides every earlier touch.

What one store's data shows

The usual answer adds a warning to the definition: last click is unfair to the channels that start journeys. True, but how unfair depends on how many of your journeys have more than one touch. One store's export puts a share on that.

One store's anonymised GA4 export, 1 January 2024 to 21 August 2026. It holds shares of revenue only: no ad spend, no order counts.

On the Journeys sheet, journeys with 1 touch hold 79.5% of revenue. For that revenue, last click is not wrong, because nothing came before the one touch. First click, data-driven and every other rule give the same answer when a journey has a single touch.

The longer journeys hold 20.6% on the Journeys sheet (12.2% + 5.4% + 3.0%), about a fifth of revenue. That fifth is where the model matters, and those journeys are slow. On the Journeys sheet, journeys of two or three touches took 12.5 days to buy. Four to nine touches took 16.9 days and ten or more took 16.0 days, the Journeys sheet says.

In those journeys, last click hands the whole sale to the final touch. Everything in the days before gets nothing.

Direct tells the same story from the channel side. On the Channels sheet, it holds 57.7% of revenue under last click, first click and touched views alike. When a channel scores the same under every rule, the rule is not what shapes its number.

What the export cannot show is whether any touch caused a sale. It holds shares of revenue, not spend or orders. A credit rule, last click included, decides who gets credit after the sale. It never tests whether the sale would have happened anyway.

Why does the usual answer mislead?

It treats last click as one rule. In practice there are several, and your tools disagree on which one they mean.

• Shopify's marketing reports offer Last click, which gives the sale to the final channel, direct visits included.
• Shopify also offers Last non-direct click, which skips direct visits. Its help names this the default for marketing activity data, yet a report's Attribution menu starts on Last click.
• In GA4, Paid and organic last click and Last non-direct click are two names for the same model. It ignores direct traffic unless every touch on the path was direct.
• Google Ads' Last click gives all credit for the conversion to the last-clicked ad and its keyword.

So one sale can carry different last clicks. Say a buyer clicks your email, then comes back two days later by typing your address. Shopify's Last click gives that sale to Direct, while GA4's Paid and organic last click gives it to Email.

There is a second trap. GA4 uses last click in places even when your reporting model says data-driven. Google's help says user- and session-scoped dimensions use the paid and organic channels last click model, whatever model you pick. So the Traffic acquisition report, which shows session-scoped dimensions, is a last-click report. Google's help also says GA4 uses last click for all Google Ads conversions based on key events.

For the longer case against the model, read last-click attribution and what it hides.

What can last click not tell you?

It cannot tell you which channel started the journey. A buyer who saw your ad on Monday and searched your brand on Friday hands the sale to search. It cannot tell you whether the last click was needed, either. Someone who would have bought anyway, and tapped a branded ad on the way in, still gives that ad full credit.

Google's Ads help puts it plainly. Most advertisers measure on a last click basis, it says, and that ignores the other ad interactions customers may have had along the way.

That does not make last click useless. It answers one narrow question well: which channel was the final step before the sale? Use it for that, not for deciding what to cut.

What to do this week

1. Name the model behind every number. In GA4, read Reporting attribution model under Admin > Data display > Events > Attribution settings. In Shopify, check the Attribution menu in a marketing report's configuration panel. Pass: you can say which last click each weekly figure uses. Fail: someone compares a Shopify Last click figure with a GA4 one.
2. Put last click next to data-driven. In GA4, open Advertising > Attribution > Attribution models and compare Paid and organic last click with Data-driven. Pass: your main channels keep roughly the same credit, so last click is fine for weekly calls. Fail: one channel gains a lot under data-driven, so stop judging it on last click alone.
3. Hold any cut until you see the paths. Open Advertising > Attribution > Attribution paths and find the channel you plan to cut. Pass: it rarely appears before the final touch, so last click is not hiding much of its work. Fail: it shows up early in many longer paths, so last click is underpaying it.

Check the homework. Your GA4 Attribution paths export already holds the evidence. Causality Engine reads that one file and shows what each channel caused next to what last-click gave it, in 1 to 2 minutes, for €99 once (excluding VAT), refundable within 30 days. Check the homework

Sources, 1 October 2026: Get started with attribution (Google); Scopes of traffic-source dimensions (Google); Key event attribution models report (Google); About attribution models (Google); Marketing reports (Shopify)

Related answers

• All Attribution models questions
• How to see last click attribution in GA4, step by step
• Attribution model, defined
• Causal attribution, explained