What is position-based attribution?
Position-based attribution, also called U-shaped attribution, gives 40% of the credit to the first touch, 40% to the last and shares 20% across the middle. Here is how it works, a worked SAR example and when it fits.
Position-based attribution is a multi-touch attribution model that gives 40% of the credit for a conversion to the first touchpoint, 40% to the last, and splits the remaining 20% equally across the touches in between. Also called U-shaped attribution, it rewards both the channels that introduce buyers and the channels that close the sale.
How does position-based attribution work?
The model fixes the weight of each position on the path, then divides the middle share by the number of middle touches.
| Position | Share of credit |
|---|---|
| First touch | 40% |
| All middle touches (shared equally) | 20% |
| Last touch | 40% |
Paths with only one or two touches cannot follow the 40/20/40 split, and tools handle them differently, so check yours before comparing reports.
Position-based attribution example
An illustrative Saudi customer places a SAR 2,000 order after four touches:
| Touchpoint | Position | Credit |
|---|---|---|
| Snapchat ad click | First | SAR 800 |
| Non-brand search ad | Middle | SAR 200 |
| Email click | Middle | SAR 200 |
| Brand search ad | Last | SAR 800 |
With five touches, the three middle touches would share SAR 400, about SAR 133 each.
When should you use position-based attribution?
It fits journeys with a clear opener and closer, which covers most ecommerce and many B2B paths. It stops brand search from absorbing credit that prospecting earned. Watch two limits:
- Nurture looks weak: middle touches such as email sequences and webinars share only 20%.
- Not in Google's tools: Google retired position-based in 2023, and the Google Ads attribution help now lists only last click and data-driven.
Related terms
Position-based sits between first-click and last-click attribution. Linear attribution treats every position equally instead.
How Grower helps
Grower's attribution engine de-duplicates conversions from every connected channel and app into one count, then credits each touchpoint with the model you pick, including position-based (40/20/40). You can also choose a custom model and set your own weight for each touchpoint.
Frequently asked questions
Why is position-based attribution called U-shaped?
Plot the credit for each touch along the path and the chart looks like a U: high at the first touch, low across the middle and high again at the last touch. The name describes the shape of the weights, 40% at each end and 20% shared in between, rather than any particular channel or journey type.
Can I use position-based attribution in Google Ads?
No. Google Ads offers data-driven and last click attribution only. Google retired first click, linear, time decay and position-based models in 2023 and moved conversion actions still using them to data-driven. To see position-based results, apply the model in a cross-channel attribution tool that works on your own de-duplicated conversions.
Is position-based attribution better than linear?
For most teams, yes, because it reflects that opening and closing a sale usually matter more than the touches in between. Linear is simpler and treats every touch as equal. If your nurture steps do a lot of the work, such as a demo or trial in a B2B funnel, a custom model can give those middle touches more weight.
Apply position-based attribution to every channel on one de-duplicated count: book a Grower demo, or read marketing attribution models explained to compare all the models.