Reporting attribution model GA4

 https://support.google.com/analytics/answer/10597962?hl=en

An attribution model can be a rule, a set of rules, or a data-driven algorithm that determines how credit is assigned to touchpoints along a user's path to completing important actions.

Reporting attribution model lets you select the attribution model you want to use to attribute credit in your Google Analytics 4 reports and the reports of any linked Firebase projects. Changing the reporting attribution model applies to historical and future data. Learn more Get started with attribution.

Changing the reporting attribution model is reflected in all key event reports and explorations that use event-scoped traffic dimensions, for example, Source, Medium, Campaign, and Default channel group. In Explore, you can view a full list of dimensions that are compatible with attribution. User- and session-scoped traffic dimensions, such as Session source or First user medium, are unaffected by changes to the reporting attribution model.

Note: The first click, linear, time decay, and position-based attribution models are no longer available as of November 2023. Learn more About the deprecated models.

Fractional credit

Based on your selected attribution model, you'll notice changes to the following metrics when used with event-scoped traffic dimensions: Key events, Total revenue, Purchase revenue, and Total ad revenue.

When you switch to a non-last click attribution model, you may notice decimals or "fractional credit" for the first time in these columns. This is because credit for a given key event is distributed between contributing ad interactions according to your selected attribution model.

Example
You select the Linear model. A user follows the path keyword1 > keyword2 and then converts. In this case, each keyword will display 0.5 in the Key events column from that key event.

Channels that can receive credit

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Key event lookback window

Users can trigger key events days or weeks after interacting with your ad.


The conversion window determines how far back in time a touchpoint is eligible for attribution credit. For example, a 30-day conversion window will result in January 30th conversions being attributed only to touchpoints occurring from January 1-30.

The conversion window applies to all attribution models and all conversion types. Changes to the conversion window apply going forward and will be reflected in all reports within your Analytics property.

For Acquisition conversion events (first_open and first_visit), the default conversion window is 30 days. You can switch to 7 days if you have different attribution needs.

For all other conversion events, the default conversion window is 90 days. You can also choose 30 days or 60 days.
Note: The key event lookback window you choose also applies to session attribution.