The U-shaped attribution model (also called position-based attribution) is a multi-touch framework that assigns the largest share of credit to the first and last touchpoints in a journey, with the remainder spread across middle interactions. The most common split is 40% to first touch, 40% to last touch, and 20% divided evenly among everything in between.
How U-shaped attribution distributes credit
Example: a prospect has five touchpoints before converting — paid search ad, blog post, webinar, nurture email, and pricing-page visit. Under classic U-shaped weighting:
- Paid search (first): 40%
- Blog and webinar (middle): 10% each
- Nurture email (middle): 10%
- Pricing page (last): 40%
If there are more middle touches, the 20% middle pool is divided equally — ten middle touches would receive 2% each.
U-shaped vs. other position-based variants
In B2B funnels, some teams adapt the anchors:
- Classic U-shaped: first touch + last touch before conversion.
- Lead-creation variant: first touch + the touch that created the lead or MQL, with 20% for nurture in between — common when marketing optimizes for lead volume.
Document which anchors you use. Changing definitions mid-quarter changes the story without changing performance.
When U-shaped attribution fits
- Multi-channel journeys where you need credit for both discovery and conversion.
- Teams graduating from single-touch without jumping straight to complex custom models.
- Shorter B2B cycles (roughly sub-90 days) where last-touch still reflects a meaningful conversion moment.
Limitations
- Middle touches can look negligible on long journeys with dozens of interactions.
- Arbitrary weights: 40/40/20 is a convention, not a law of buyer behavior.
- Misses opportunity creation: For sales-led motions, the handoff from marketing-qualified to sales-qualified may matter more than the last touch — which is why many B2B teams prefer the W-shaped model.
U-shaped attribution works best as one lens in a multi-touch portfolio — compared alongside linear and first-touch views to see how credit shifts.