How to Build a Multi-Touch Attribution Model

# How to Build a Multi-Touch Attribution Model for Paid Campaigns

In the world of Australian digital marketing, relying on 'Last-Click' attribution is like giving the winning goal-scorer all the credit while ignoring the players who spent the whole match setting up the play. Multi-touch attribution (MTA) allows you to see the full customer journey—from that first discovery on Facebook to the final conversion via a Google Search ad—ensuring your budget is allocated to the channels that actually drive growth.

Building an MTA model allows you to stop guessing which ads are working and start investing in the entire funnel with confidence.

Prerequisites: What You’ll Need

Before we dive into the setup, ensure you have the following ready:

• Google Analytics 4 (GA4) installed: This is the foundation for modern tracking.
• Google Tag Manager (GTM): To manage your conversion tags efficiently.
• Standardised UTM Parameters: A consistent naming convention for your URLs.
• Conversion Tracking: Defined 'Key Events' (formerly conversions) in GA4 (e.g., lead form submissions or purchases).
• Access to Ad Platforms: Admin access to Google Ads, Meta Ads Manager, etc.

---

Step 1: Standardise Your UTM Naming Convention

Multi-touch attribution is only as good as the data you feed it. If one person labels a campaign FB_Spring_Sale and another uses facebook-ads-september, your data will be fragmented.

Create a shared spreadsheet for your team to ensure every link uses the same utm_source, utm_medium, and utm_campaign logic. In Australia, it’s common to include the state or city if you run localised campaigns (e.g., utm_content=brisbane-northside).

Step 2: Define Your Conversion Events (Key Events)

You cannot attribute value if you haven't defined what 'value' is. In GA4, navigate to Admin > Data Display > Key Events. Ensure you have toggled on the events that matter to your business, such as generate_lead or purchase.

Step 3: Link Your Paid Accounts to Google Analytics 4

To see how your paid campaigns interact with organic traffic, you must link your accounts. Go to Admin > Product Links. Link your Google Ads account and, if applicable, your Search Console.

For non-Google platforms (like Meta or LinkedIn), ensure your UTMs are perfect, as these won't have a direct 'native' link like Google Ads does.

Step 4: Access the GA4 Attribution Settings

By default, GA4 uses a 'Data-Driven' attribution model. To understand or change this, go to Admin > Data Display > Attribution Settings.

Here, you can choose the reporting attribution model. While 'Data-Driven' is recommended as it uses machine learning to distribute credit, you should also look at the 'Reporting time' settings to decide if you want credit attributed to the time of the conversion or the time of the ad interaction.

Step 5: Explore the Model Comparison Tool

This is where the magic happens. Navigate to Advertising > Attribution > Model Comparison.

This tool allows you to compare how different models (e.g., Last Click vs. First Click vs. Data-Driven) value your paid channels.

• First Click: Shows you which ads are 'opening' the door and introducing your brand to Brisbane locals.
• Last Click: Shows you which ads are 'closing' the deal.
• Data-Driven: The balanced view.

Step 6: Analyse the Conversion Paths Report

Go to Advertising > Attribution > Conversion Paths. This report visualises the 'touchpoints' a user takes.

Notice how many customers interact with your brand 3 or 4 times before buying? This is the evidence you need to justify spending on 'Top of Funnel' awareness ads.

Step 7: Set Up a BigQuery Export (Advanced but Recommended)

For Australian businesses with high transaction volumes, the standard GA4 interface can be limiting. By linking GA4 to BigQuery (Google’s cloud data warehouse), you can access raw event data.

This allows you to build custom SQL models to weigh touchpoints exactly how you want (e.g., giving 50% credit to the first and last click, and distributing the rest in the middle—known as a 'Position-Based' model).

Step 8: Visualise the Data in Looker Studio

Raw data is hard to read. Use Looker Studio to create a dashboard for your stakeholders. Connect your GA4 property and create charts that show 'Cost per Acquisition' across different attribution models.

This helps you explain to your team why a Facebook ad might have 0 'Last Click' conversions but is actually present in 40% of all successful conversion paths.

Step 9: Adjust Your Bidding Strategy Based on Insights

Once you see that certain 'Awareness' campaigns are consistently the 'First Click' for high-value customers, don't pause them just because their direct ROI looks low. Instead, adjust your Google Ads or Meta bidding to 'Maximise Conversions' while acknowledging their role in the multi-touch journey.

---

Pro Tips for Better Attribution

• Account for Offline Conversions: If you are a local Brisbane service business (like a plumber or lawyer), people might click an ad but call you on the phone. Use a call tracking tool like Delacon or WildJar and integrate it with GA4 to ensure those 'offline' touches are counted.
• Mind the 'Cookie' Window: Most browsers now limit tracking cookies (ITP). Don't expect to see a 90-day journey perfectly; focus on the 7-to-14-day window for the most accurate data.
• Exclude Internal Traffic: Ensure your own office IP address is excluded in GA4 settings, or your team’s clicks will skew your attribution paths.

Common Mistakes to Avoid

• Ignoring Direct Traffic: If 'Direct' is your biggest conversion source, it usually means your attribution is broken or your brand awareness is high but untracked. Check your UTMs.
• Over-valuing Brand Search: Often, users click a 'Brand' ad (searching for your specific business name) as the last step. A last-click model gives the brand ad 100% credit, but a multi-touch model will show that a 'Generic' search or social ad did the heavy lifting earlier.
• Comparing Apples to Oranges: Don't compare 'In-Platform' Meta data to GA4 data directly. Meta uses a 'View-Through' attribution (counting people who saw the ad but didn't click), while GA4 generally only tracks clicks.

Troubleshooting

• Problem: My GA4 data doesn't match my Google Ads data.

• Problem: I can't see 'Conversion Paths' in GA4.

• Problem: All my traffic shows as 'Unassigned'.

Next Steps

Now that you've moved beyond last-click attribution, it’s time to refine your budget. Review your 'First Click' heavy-hitters and consider increasing their budget by 10% to see if it leads to a total lift in conversions two weeks later.

Need help setting up advanced tracking or BigQuery exports? The team at Local Marketing Group can help you navigate the technical setup to ensure your Brisbane business is tracking every dollar accurately. Contact us today to book a strategy session.