Attribution Guide
Your ad platforms are all lying to you. Here's how to find the truth.
Here's a scenario we see every week: Meta Ads reports $50K in attributed revenue. Google Ads reports $40K. Klaviyo reports $30K. But total Shopify revenue is $80K. The math doesn't add up because each platform takes credit for the same purchases through different attribution windows and models.
This isn't a glitch — it's how attribution works. Each platform uses self-serving attribution that makes their ads look as good as possible. Meta uses a 7-day click, 1-day view window. Google uses 30-day click. They both claim the same customer who clicked a Meta ad on Tuesday and a Google ad on Thursday before buying on Friday.
If you make budget decisions based on platform-reported ROAS, you're optimizing based on inflated numbers. Here's how to get closer to the truth.
40-60%
Revenue Over-Reported by Platforms
3+
Attribution Models to Compare
$23M+
Revenue We Track for Clients
150+
Brands Managed
How to fix this — step by step
Use Shopify revenue as your single source of truth
Shopify records every actual transaction. It doesn't have an attribution model — it just counts orders and revenue. This is your ground truth. Every week, compare total Shopify revenue to the sum of revenue reported by Meta, Google, Klaviyo, and any other channel. The gap between the two numbers tells you how much your platform attribution is inflated. This number is your "attribution tax" — and it's usually 30-60%.
Set up UTM parameters on every ad and link
UTM parameters let GA4 track where clicks actually come from. Every ad URL should include: utm_source (facebook, google, tiktok), utm_medium (paid, email, organic), utm_campaign (the campaign name), and utm_content (the specific ad variant). In GA4, the Acquisition report then shows which sources drive actual sessions and conversions. This gives you a click-based attribution view that's independent of each platform's self-reporting.
Compare platform ROAS with GA4 ROAS for each channel
Meta says 5x ROAS? Check what GA4 says for the same campaign. GA4 uses last-click attribution by default, which is conservative. The "true" ROAS is usually somewhere between GA4's conservative number and the platform's inflated number. If Meta reports 5x and GA4 reports 2x, your real ROAS is likely 3-3.5x. Do this comparison monthly for every channel. It reveals which platforms exaggerate most.
Run channel-level incrementality tests
The gold standard: pause a channel and see what happens to total revenue. If you pause Meta Ads for 5 days and Shopify revenue drops 30%, Meta was driving roughly 30% of your revenue (adjusting for natural fluctuation). If revenue barely changes, those ads weren't incremental — they were claiming credit for organic or email-driven purchases. Run these tests quarterly for your biggest spend channels. It's uncomfortable but it's the truth.
Use blended ROAS for budget allocation decisions
Stop making budget decisions based on individual platform ROAS. Calculate blended ROAS: total Shopify revenue / total ad spend across all platforms. This is the only number that can't be gamed by attribution models. If blended ROAS is 3.5x and you're comfortable with that, it doesn't matter if Meta claims 5x and Google claims 4x — what matters is the total system is profitable. Allocate more budget to channels where pausing them causes the biggest revenue dip (incrementality).
Want us to handle this?
Attribution isn't a set-it-and-forget-it problem. As you add channels, change budgets, and shift strategy, the attribution picture changes. We manage multi-channel attribution for eCommerce brands — building custom dashboards, running incrementality tests, and making budget allocation recommendations based on real data, not platform spin.
If you want a clear picture of what's actually driving your revenue, we'll build that report for you.
Questions our best clients asked first
Want to know which ads are actually driving your revenue?
We'll build a cross-channel attribution report comparing platform data, GA4, and Shopify revenue — so you can see exactly where your money is working and where it's wasted.
Pick a Time15 minutes. No pitch deck. Just your data and our honest take.
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