Understanding Attribution in eCommerce – A Shopify Expert’s Guide

If you have an online business, you have likely asked yourself, "What ads are really generating sales for me, and where should I spend more?"

As a Shopify Plus Partner and a performance marketer specialising in eCommerce brands, our team at Seventh Triangle answers this question on a daily basis.

The answer, more often than not, comes down to attribution, or how you attribute success to your marketing channels.

Who Should Read This?

This guide is designed for store owners/marketing managers operating their business in countries such as India, Australia, the US, or Europe.

• Run ads across multiple platforms (Google Ads, Meta, etc.)

• Need an accurate method to measure performance across various channels

• Need to make smarter budget calls

If you are spending X on Google Ads and Y on Meta Ads, and wish to know which ads are pulling their weight? This will help.

Why Attribution in eCommerce Is Tricky?

Giving credit for a sale isn’t always straightforward.
It’s not just about the first ad someone clicked or the last one they saw.

In fact, over 50% of sales in fast-growing D2C brands involve more than one touchpoint.

Here’s an example:

1. A shopper sees your Meta ad for the first time.
   
   

2. A week later, they Google your brand and click a search ad.
   
   

3. Finally, they click a retargeting ad and buy.
   
   

So… which ad gets the credit?

There is no easy way to credit a sale.

It’s not just about the first ad someone clicked on, or the last ad they saw.

Indeed, sales involving more than one touchpoint are already higher than 50% within fast-growing D2C companies.

Here's an example:

• A person sees your ad from Meta for the very first time.

• They Google your brand a week later, then they click a search ad.

• Finally, they click a retargeting ad and buy.

Well… what ad gets the credit?

First-Click vs Last-Click Attribution

If you're only using one channel, First-Click or Last-Click attribution will probably be sufficient.

• Last-Click → Gives all the credit to the last ad clicked. It usually tends to favour brand searches or retargeting ads.

• First-Click → Gives all the credit to the first touch. Typically, rewards are awareness campaigns.

But if you're running multi-channel marketing, these models can paint a very skewed picture.

How GA4’s Data-Driven Attribution (DDA) Works

Think about a customer journey as a kind of relay race:

• Every runner = an ad or a touchpoint

• The baton = the customer's interest

• The finish line = the sale

In Last-Click, for example, only the final runner gets the medal.

In First-Click, only the first runner gets it.

GA4's Data-Driven Attribution does something smarter: it splits the medal between runners, based on how important each leg was.

• If it were a Google Search ad that kicked off the journey, it would get a bigger share.

• If it were a Meta ad that re-engaged the shopper along the way, it gets partial credit.

• If a retargeting ad closed the sale, it gets the credit.

This way, every channel that contributed gets fair recognition.

Why GA4 Can Favour Google Ads

Although GA4 is more intelligent than First/Last Click, it has two major biases:

1. Ecosystem Bias

GA4 is a part of Google.

And it has perfect data on Google Ads, including campaigns, keywords, and even cross-device behaviours.

For Meta and others, all they receive is the partial data (most often, due to privacy updates).

Result? Google Ads looks like a better option just because GA4 can “see” it so much more clearly?

2. Touchpoint Bias

Google Ads frequently uses bottom-of-the-funnel ad campaigns, brand search, and retargeting ads

GA4, on the other hand, appears to favour the final touches even if other sources were primarily responsible earlier.

The Bottom Line

Google Ads may look like the MVP in GA4 reports, but that doesn’t always mean it was the MVP.

If you want real, apple-to-apple comparisons between channels, you need to look at more than one attribution model.

How to Compare Attribution Models in GA4 (Step-by-Step)

Step 1 - Open the Attribution Models Report

• Go to Advertising → Attribution → Attribution models

• Choose your key conversion event, such as Purchase.

• Select the date range

Step 2 – Compare Two Models Side-by-Side

• Column 1: Data-Driven Attribution DDA

• Column 2: Last-Click Attribution

Step 3 - Interpret the % Change

• If Google Ads slides down Last Click → It's mostly closing sales, not starting them.

• If Meta Ads rise in Last Click → They are probably driving more early-stage awareness.

Step 4 – Plan Your Budgets Smarter

• Use DDA for bidding on Google Ads.

• Use the comparison to value awareness channels more equitably.

• Consider overspending on those channels that are basically all retargeting, and check periodically to avoid over-funding.

Pro Tip: Ensure GA4 channel groupings are set correctly, as wrong labels lead to wrong conclusions. Also, notice that DDA needs volume: Google wants 200+ conversions/mo.

Conclusion

"Attribution is about recognising the true story underlying the sale and not about identifying some 'perfect' mode"

Once you do that, you’re able to make intelligent ad spend decisions, whether you’re advertising in Delhi, Sydney, New York, or Berlin.

How Seventh Triangle Can Help

We’ve helped Shopify brands across India, Australia, the US, and Europe get their attribution right, so they stop guessing and start scaling.

Here’s what we do:

• Set up accurate tracking for Google Ads, Meta Ads, and other platforms
  
  

• Build clean channel groupings in GA4 for reliable reporting
  
  

• Compare attribution models so you see the real performance picture
  
  

• Give clear, actionable insights to improve ROAS
  
  

If you want data you can trust and budgets that work harder, reach out to us. We’ll help you scale smarter with our performance marketing experts.