U-shaped attribution model
A position-based model that assigns 40% of revenue credit to the first touchpoint, 40% to the lead-creation touchpoint, and spreads the remaining 20% across all middle interactions. Designed for demand-gen teams that care about both acquisition and conversion.
What is the U-shaped attribution model?
The U-shaped attribution model, sometimes called the "bathtub" model due to its credit distribution curve, is a position-based multi-touch attribution approach. It recognises two milestones as especially significant in the buyer journey: the first touchpoint (when the prospect discovered the brand) and the lead-creation touchpoint (when they converted from anonymous visitor to identified lead).
Each of those milestones receives 40% of the total revenue credit. The remaining 20% is divided equally among all touchpoints that occurred between the two milestones. If there are no middle touches, the model collapses to 50/50 between first and lead creation.
The model was developed to address the failure mode of single-touch models: first-touch ignores closing-channel performance, last-touch ignores acquisition performance. U-shaped preserves a strong signal at both ends. Its limitation is that it stops at lead creation and does not track the progression from lead to opportunity to close, which is where the W-shaped model picks up.
How credit is distributed: the 40/20/40 split
The U-shaped model distributes credit across three zones:
- 40First touch: the channel or campaign that introduced the account to your brand for the first time.
- 20Middle touches: all interactions between first touch and lead creation, split equally among however many there are.
- 40Lead-creation touch: the interaction immediately preceding or directly associated with the prospect becoming an identified lead in your CRM.
| Touchpoint | Zone | Credit weight |
|---|---|---|
| Organic search visit | First touch | 40% |
| LinkedIn ad click | Middle (1 of 2) | 10% |
| Webinar attendance | Middle (2 of 2) | 10% |
| Form fill (lead created) | Lead creation | 40% |
Compare with linear attribution (25% to each touch in this example) and first-touch (100% to the organic visit). U-shaped splits the difference and emphasises both meaningful milestones.
When to use U-shaped attribution
U-shaped attribution fits teams that have outgrown single-touch models but do not yet have a formalised opportunity-stage pipeline. It is especially useful when:
- Demand-gen and conversion-rate teams share attribution goals and each needs their channels credited meaningfully
- Lead volume and lead quality are both KPIs: first touch measures acquisition quality, lead creation measures conversion effectiveness
- The company does not yet have clean opportunity-creation event tracking required by the W-shaped model
Once your pipeline tracking matures to include opportunity creation as a distinct event, the natural upgrade is W-shaped attribution, which adds a third 30% milestone at opportunity creation and is better suited to long B2B cycles with a formal sales stage structure.
Pros and cons
Pros
- Balances awareness and conversion credit across two meaningful milestones
- Reduces the bias of single-touch models without requiring a full W-shaped pipeline structure
- Works well for teams that have reliable first-touch and lead-creation event tracking
- Easy to explain: 40% first, 20% middle, 40% lead creation
Cons
- ✕Ignores the opportunity-creation milestone important to B2B sales teams
- ✕The 40/20/40 split is a convention, not a proven universal weighting
- ✕Requires clean lead-creation event tracking; gaps produce incorrect milestone assignment
- ✕Less informative than W-shaped for companies with a formal sales pipeline stage structure
How AttriByte handles U-shaped attribution
AttriByte identifies the lead-creation milestone from your CRM data in the warehouse. The model automatically classifies each touchpoint into first-touch, middle, or lead-creation zone and applies the 40/20/40 split without requiring custom SQL. Because the same identity graph powers all six models, U-shaped runs on the same complete journeys as first-touch and W-shaped, making the comparisons directly meaningful.
If your lead-creation event is inconsistently logged in the CRM, AttriByte surfaces the data quality issue before it silently distorts the model. Clean input data produces trustworthy attribution; AttriByte flags gaps rather than hiding them.
For teams that want to graduate from U-shaped to W-shaped as their pipeline tracking matures, the upgrade in AttriByte requires no reconfiguration of the data pipeline: both models run simultaneously and the W-shaped view becomes available as soon as opportunity-creation events appear in the warehouse. See the platform details on the product page.
Explore other models
Run U-shaped next to W-shaped and four other models
AttriByte shows you the 40/20/40 split alongside every other attribution model so you can see what each milestone is worth.