Every attribution model looks at the exact same customer data and tells a slightly different story. None of them is "correct" in an absolute sense — each one optimizes for a different question. The mistake isn't picking the wrong model; it's not knowing which question you're actually trying to answer.
| Model | How credit is split | Question it answers |
|---|---|---|
| First-touch | 100% to the first interaction | What creates awareness / brings in new people? |
| Last-touch | 100% to the final interaction before conversion | What's there the moment someone finally decides to buy? |
| Linear | Equal split across every touchpoint | A simple, defensible baseline when you don't want to argue about weighting |
| Time-decay | More credit to touchpoints closer to conversion | Which recent touches mattered most, when recency itself is meaningful |
| Position-based (U-shaped) | Large fixed share to first + last (e.g. 40/40), rest split across the middle | Balancing 'what found them' against 'what closed them' |
| Data-driven | Calculated per-account from actual conversion patterns | The most accurate picture, given enough data to calculate it from |
First-touch and last-touch are covered in full depth, with a worked example, in first-touch vs. last-touch attribution. Linear, time-decay, and position-based are covered together, alongside data-driven, in multi-touch attribution. This article is the decision layer on top of both — how to actually pick, given your specific situation.
It's worth noting that Google Ads itself moved away from offering first-click, linear, time-decay, and position-based as selectable options — they're no longer supported, with accounts automatically upgraded to data-driven attribution as the default. That's a meaningful signal about where the industry has landed: fixed-rule models are a reasonable starting point, but a data-driven approach — where the weighting comes from your actual conversion patterns instead of an arbitrary formula — tends to outperform them once there's enough data to support it.
If you're just starting to look past last-click reporting:
If your sales cycle is very short and mostly single-session:
If you have meaningful, ongoing conversion volume:
If your real conversion happens outside your website entirely (B2B):
Every model on this list is trying to summarize the same underlying thing: the actual sequence of touchpoints a customer went through. If you can already see that full sequence — every channel, every campaign, every gap in between — the exact model you apply on top of it becomes a much lower-stakes decision, because you're never blind to what's actually happening. That visibility, more than any specific model, is what separates useful attribution from a report nobody trusts. If you haven't already, start with what marketing attribution actually is and work outward from there.
Conversion tracking and attribution consultant. Spends most days inside Google Tag Manager, GA4, and server-side tracking setups, helping ecommerce and B2B teams figure out where their customers actually came from. More about Abdul →