Marketing / Ad Ops
What Is an Attribution Model?
An attribution model is the rule for assigning credit across the marketing touchpoints in a customer journey, and the model you pick changes the story your data tells. The same journey can read as 100 percent Meta under last-touch, 100 percent Google under first-touch, or 25 percent each under linear, so channel ROAS can differ by 3 to 5 times. Last-touch is the platform default and over-credits performance channels by 30 to 100 percent.
An Attribution Model is the rule for assigning credit across the marketing touchpoints in a customer journey. Different models tell different stories about the same data — and the choice changes channel-allocation decisions.
The major models
- First-touch: 100% credit to the first channel that touched the customer. Over-credits awareness channels.
- Last-touch: 100% credit to the last channel before conversion. Default in most platforms. Over-credits performance / retargeting.
- Linear multi-touch: equal credit across all touches.
- Time-decay: more credit to recent touches.
- Position-based (U-shaped): 40% first, 40% last, 20% middle.
- Data-driven: algorithmic credit assignment using observed conversion patterns.
Example: same journey, different stories
Customer journey: Google brand search → Meta retarget → email open → Meta retarget click → purchase. Under last-touch: 100% Meta. Under first-touch: 100% Google. Under linear: 25% each. Channel ROAS by attribution model can differ by 3-5x.
How CFOs cut through
- Use MER for top-line marketing efficiency (no attribution required)
- Run incrementality tests (geo holdouts, paused-channel) to measure true lift
- Compare blended CAC vs paid CAC to size the organic halo
- Track new vs repeat customer at the CRM level (not the ad platform)
The most common mistake
Treating last-touch as truth. Last-touch over-credits performance channels by 30-100% and under-credits brand. Channel decisions made on last-touch alone systematically over-fund retargeting and under-fund brand/awareness investments.
Frequently Asked Questions
Why does attribution model matter?
Different models tell different stories. Allocation decisions change.
What's the most common model?
Last-touch — default in most platforms. Biased toward performance channels.
How do CFOs cut through?
MER + incrementality testing + blended-vs-paid CAC comparison.
Related Terms
- First-touch vs last-touch
- What is incrementality?
- What is MER?
- What is ROAS?
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