Attribution model

Attribution in plain English

Imagine someone finds your blog through Google, sees your Instagram a week later, then clicks a Google ad and books. Which channel earned the booking? Different attribution models give different answers, and that can change where you decide to spend money.

Common attribution models

• First touch: all credit goes to the first interaction. Useful for understanding what introduces people to you.
• Last touch (last click): all credit goes to the final interaction before converting. Simple, but it undervalues earlier channels.
• Linear: credit is shared equally across every touchpoint.
• Time decay: touchpoints closer to the conversion get more credit.
• Position-based (U-shaped): most credit goes to the first and last touches, with the rest shared in between.
• Data-driven: an algorithm assigns credit based on how each touchpoint actually affects the chance of converting.

What GA4 and HubSpot use

Google Analytics 4 uses data-driven attribution by default, with last-click options available. Google retired the first-click, linear, time-decay and position-based models from GA4 in 2023. HubSpot's attribution reports offer a wider range of models, which is useful for seeing how contacts and deals were influenced over time.

How to use attribution sensibly

1. Get tracking right first. Clean UTM parameters and key events for forms, calls and bookings matter more than the model.
2. Compare models rather than trusting one. If a channel looks strong in first touch but weak in last touch, it is probably introducing people to you.
3. Connect to real outcomes. Credit for leads is useful. Credit for customers who pay is better.
4. Use it to guide budget, not settle arguments. Attribution is an estimate.

Why it matters for CRO

Attribution shows which channels bring visitors who go on to enquire, so you can focus CRO work on the pages and journeys those visitors use, and calculate a realistic customer acquisition cost per channel.

Related terms

• UTM parameters
• Customer acquisition cost (CAC)
• Customer journey
• Conversion rate

How WebManics can help

We set up GA4, Tag Manager and HubSpot so every enquiry is tracked with its source, then report on what is actually bringing in work in plain English. Get a tracking check as part of our free website conversion audit, or ongoing reporting through our CRO Growth Retainer.