Marketing ROI Calculator

Attribution Models Compared: First-Touch vs Last-Touch vs Linear vs Time-Decay vs Data-Driven

The same customer journey gets credited completely differently depending on the attribution model you pick. Here is what each model does, where it lies to you, and when to use it.

TL;DR: The Key Differences

First-Touch: credits discovery — flatters awareness channels, hides what closes

Last-Touch: the platform default — flatters retargeting & branded search, hides what started the journey

Linear / Time-Decay / Position-Based: rules-based attempts to split credit across the journey

Data-Driven: algorithmic credit from your own paths — most accurate, but only with clean, high-volume data

The catch: no model is “true.” Each platform applies its own, so the same sale is counted more than once across Meta, Google, and Shopify

First-Touch
100% to the first touchpoint

Pros

  • Simple to understand
  • Rewards demand creation
  • Good for top-of-funnel

Cons

  • Ignores everything after discovery
  • Over-credits awareness channels
  • Hides what closes the sale

Best for: Brands focused on net-new demand and awareness

Last-Touch
100% to the final touchpoint

Pros

  • Platform default
  • Easy to report
  • Rewards channels that close

Cons

  • Ignores discovery and nurture
  • Over-credits branded search & retargeting
  • Punishes upper funnel

Best for: Short, simple buying journeys

Linear
Equal credit to every touchpoint

Pros

  • Acknowledges the full journey
  • No single-channel bias
  • Easy to explain

Cons

  • Treats a banner view like a demo
  • Rarely matches real influence
  • Can flatter weak touchpoints

Best for: Long journeys where every step genuinely matters

Time-Decay
More credit to touchpoints nearer the sale

Pros

  • Reflects recency of intent
  • Balances funnel stages
  • Sensible default for considered buys

Cons

  • Still under-credits discovery
  • Decay rate is arbitrary
  • Needs full-path data

Best for: Considered purchases with a clear closing run

Position-Based (U-Shaped)
40% first, 40% last, 20% to the middle

Pros

  • Rewards both discovery and close
  • Keeps nurture visible
  • Popular compromise

Cons

  • The 40/20/40 split is a guess
  • Mid-funnel under-valued
  • Not data-driven

Best for: Teams that care about both creation and conversion

Data-Driven (DDA)
Algorithmic credit from your real conversion paths

Pros

  • Based on your actual data
  • Adapts to your funnel
  • Most accurate when fed clean data

Cons

  • Needs volume & full-path signal
  • A black box to most teams
  • Garbage-in, garbage-out

Best for: High-volume brands with reliable tracking

Same Journey, Different Credit
How one €200 order gets split across four touchpoints (illustrative)

Journey: Google search → Meta retargeting → Email → Purchase (€200)

ModelGoogleMetaEmail
First-Touch€200€0€0
Last-Touch€0€0€200
Linear€66.67€66.67€66.67
Position-Based€80€40€80

Same journey, same €200 — but Google looks like a hero under First-Touch and worthless under Last-Touch. Now multiply this across thousands of orders and you see why two dashboards never agree, and why blended metrics like MER exist.

So Which Model Should You Use?

There is no single “correct” attribution model — only the one that matches your buying journey and the decision you are trying to make. A short, impulse-buy journey survives last-touch; a long, multi-session, considered purchase does not.

The bigger trap is comparing channels across different models. Meta defaults to its own view-through-inclusive model, Google to data-driven, and Shopify to last-non-direct click. Add the dashboards together and you will “sell” far more than you actually did. That is why most operators anchor strategy on a blended, un-double-countable number (MER) and use per-model attribution only for tactical optimisation.

💡 Rule of thumb: pick one model as your internal standard, hold it constant, and reconcile platform numbers against Shopify as your source of truth.