Glossary · Attribution
What is position-based attribution?
Position-based attribution, also called U-shaped attribution, is a multi-touch model that gives 40% of the credit to the first touch, 40% to the last touch and splits the remaining 20% evenly across the touches in between.
Also called: U-shaped attribution, 40-20-40 attribution
Updated
How is position-based attribution calculated?
First touch: 40% · Last touch: 40% · Each middle touch: 20% ÷ (n − 2)
With exactly two touches, each gets 50%. With one, it gets everything. The 40/20/40 split is a convention, not a law; some tools let you change it. A W-shaped variant adds a third anchor — usually the lead or sign-up touch — and gives 30% each to first, lead and last, with 10% for the rest.
Position-based attribution example
A $200 annual plan follows five sessions: Google organic, newsletter, X, comparison page via Bing, direct. Google (first) gets $80, direct (last) gets $80, and the three middle touches share $40 — about $13.33 each. Compared with linear ($40 each), the discovery and closing channels gain and the middle loses.
Why position-based attribution matters
It encodes a sensible belief: the touch that introduced someone and the touch that converted them matter most, but the journey in between isn't worthless. For SaaS with a mix of content-led discovery and intent-led closing, it's often the most balanced single model.
Trade-offs
- The 40/40 weights are arbitrary and can't be validated from the data.
- Nurturing channels (newsletters, docs, webinars) get little credit on long paths.
- Like every rule-based model, it only sees tracked touches; offline and private shares are invisible.
How VisitTrack computes position-based attribution
Position-based (40% first, 40% last, 20% across the middle; 50/50 for two touches) is one of the five models VisitTrack's Revenue tab computes from each paying visitor's sessions, next to first touch, last touch, linear and time decay. Totals always reconcile with real revenue. See revenue attribution.
Frequently asked questions
What is U-shaped attribution?
U-shaped attribution is another name for position-based attribution: 40% of the credit to the first touch, 40% to the last, and 20% spread across the touches in between. The credit chart looks like a U.
What is the difference between U-shaped and W-shaped attribution?
U-shaped emphasizes two touches, the first and last. W-shaped adds a third key touch, usually lead creation or sign-up, and gives about 30% each to the three with 10% left for the rest.
Related terms
- Multi-touch attributionMulti-touch attribution is any attribution approach that divides the credit for a conversion across several of the touchpoints that preceded it, instead of giving it all to the first or last one.
- Linear attributionLinear attribution is a multi-touch attribution model that splits the credit for a conversion equally across every touchpoint in the customer's path.
- Time-decay attributionTime-decay attribution is a multi-touch attribution model that gives every touchpoint some credit for a conversion, but more to touches that happened closer in time to the conversion.
- First-touch attributionFirst-touch attribution is an attribution model that gives 100% of the credit for a conversion or payment to the source of the visitor's very first visit, ignoring every visit that came after it.
- Last-touch attributionLast-touch attribution is an attribution model that gives 100% of the credit for a conversion to the source of the last visit before it happened.
Tools and guides
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