W-shaped attribution (three key milestones)
W-shaped attribution extends the U-shaped idea by recognizing three milestone interactions rather than two: the first touch, the lead-creation touch, and the opportunity-creation (or closing) touch. Each milestone receives a large fixed share — commonly 30% apiece — and the remaining credit is spread across other touches. It is popular in B2B funnels with defined lifecycle stages.
What this means
W-shaped attribution is a multi-touch heuristic built for B2B-style funnels with named stages. It treats three interactions as pivotal: the first touch (awareness), the lead-conversion touch (the form fill or signup that creates a lead), and the opportunity-creation touch (when sales qualifies the deal). In a common form, each milestone gets ~30% and the remaining ~10% is split among the in-between touches.
The name comes from the credit curve: two peaks like a U, plus a third peak in the middle, forming a W.
Strengths and limits
W-shaped rewards the marketing that drives the stage transitions that matter to revenue, which makes it intuitive for teams that already track lead and opportunity stages in a CRM. Its weakness is the same as all rules-based models: the 30/30/30/10 weights are conventions, not measurements, and the model requires reliable milestone stamping. If your lead or opportunity timestamps are wrong, the credit lands on the wrong touch.
For journeys with more than three meaningful stages, practitioners sometimes extend the idea into 'full-path' attribution.
- First touch milestone: ~30%
- Lead-creation milestone: ~30%
- Opportunity-creation milestone: ~30%
- Other touches: share the remaining ~10%
How it appears in analytics and logs
Three spikes of credit along a path indicate a W-shaped model keyed to lifecycle milestones; channels that touch users between milestones will always look minor here.
Diagnostic use case
Use W-shaped attribution in funnels with explicit milestones — first touch, lead created, opportunity created — when you want each stage-defining interaction to carry weight.
What WebmasterID can help detect
WebmasterID captures first-party events you can map to funnel milestones, so you can identify which touchpoints coincided with lead and opportunity creation in your own data.
Common mistakes
- Applying W-shaped without reliable lead/opportunity timestamps.
- Treating the 30/30/30/10 weights as empirical.
- Using it on funnels that lack defined milestones.
Privacy and accuracy notes
W-shaped attribution keys credit to recorded funnel-stage events, not to identity. It depends on accurately stamping which touch created the lead and the opportunity.
Related pages
- U-shaped attribution (position-based 40/20/40)
U-shaped attribution is the position-based model in its classic form: the first interaction and the conversion-driving interaction each receive a large fixed share (commonly 40% each), and the remaining credit is split among the middle touches. It is a rules-based heuristic that values discovery and closing equally, and it is the lens many tools mean when they say 'position-based'.
- Full-path attribution (W-shaped plus the close)
Full-path attribution is the W-shaped model extended to four milestones: first touch, lead creation, opportunity creation, and the final closing interaction. Each milestone takes a fixed large share and the remaining credit is distributed across other touches. It is designed for long B2B sales cycles where the deal-closing interaction is a distinct, measurable event worth its own credit.
- Position-based (U-shaped) attribution
Position-based (U-shaped) attribution gives most credit to the first and last touchpoints — commonly 40% each — and shares the remaining 20% among middle touches. It tries to honour both discovery and closing while still acknowledging the middle. The specific weights are a convention, not a measured truth.
- Attribution analytics
Map first-party touchpoints to your funnel milestones.
Sources and verification notes
- Google Analytics Help — Attribution model overview (rules-based models)Position-based weighting is documented; W-shaped's three-milestone 30/30/30/10 split is an established B2B convention, not a single official spec.
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.