Your 4 Platforms Give You 4 Different Versions of Reality
Unified data 2 min read

Your 4 Platforms Give You 4 Different Versions of Reality

In 30 secondsGA4 says you sold 100, Google Ads says 140, Meta says 95 and Shopify says 87. None of them is lying, but none gives you the full picture: each platform measures by its own rules for attribution window, attribution model and recording moment. The error this creates is scaling the channel that attributes best, not the one that sells most. Teams that doubled their budget on Meta with an apparent ROAS of 5x discovered, when cross-referencing with Shopify, a real ROAS of 1.8x: Meta was claiming conversions from Google Ads and from organic traffic thanks to its one-day view-through window. The solution isn't choosing which platform to believe: it's having a single source of truth, your store's real revenue, cross-referenced with real spend per channel. If the sum of the revenue each ads platform attributes to itself exceeds Shopify's real revenue, you have double attribution.

Each platform measures by its own rules. It's not that they're lying: it's that they're counting different things.

Why the numbers never match

  • Different attribution windows: Google Ads uses 30 days by default, Meta can use 7 days for clicks and 1 day for views, GA4 has its own model
  • Different attribution models: last click, data-driven, view-through, linear — each assigns credit differently
  • Different recording moments: Google Ads records the conversion at the moment of the click, Shopify at the moment of the order, GA4 at the moment of the session

The result of mixing these differences: each platform shows you a version of your business that is partially correct. Its own. And none gives you the full picture.

The decision error this creates

Scaling the channel that attributes best, not the one that sells most.

I've seen teams double their Meta budget because the ROAS was 5x. When they cross-referenced with real Shopify revenue, it was 1.8x. The difference: Meta was attributing to itself conversions that came from Google Ads campaigns or organic traffic. With a 1-day view-through attribution window, any user who saw a Meta ad that day was attributed as a Meta conversion even if they had bought through another channel.

The solution isn't choosing who to believe

The solution is to have a single source of truth: your store's real revenue, cross-referenced with real spend per channel.

This means using Shopify (or your ecommerce platform) as the revenue reference, and assigning that revenue to channels by the real first or last touch point — not by what each platform attributes to itself.

It's not perfect. Attribution never is. But it's infinitely more useful than comparing numbers that measure different things.

What to do this week

  • Export your Shopify revenue per period and compare it with the sum of ROAS × spend for each ads channel
  • If the sum of what your ads platforms attribute to themselves exceeds your Shopify revenue, you have double attribution
  • Decide which will be your source of truth for investment decisions — usually Shopify or GA4 with a last-click model

Sources

Frequently asked questions

Which platform should I use as the source of truth?

Shopify (or your ecommerce platform) for real revenue. GA4 for behavior analysis. The ads platforms for the internal optimization of each channel, not for measuring overall ROAS.

How do I know if I have double attribution?

Add up the spend across all your ads channels and multiply by the ROAS each one reports. If the total attributed revenue exceeds your store's real revenue, you have double attribution.

Is there a way to have perfect attribution?

No. Perfect multi-touch attribution doesn't exist because the customer journey isn't linear. The goal is to have a consistent methodology and always use it the same way to compare periods.