Cross-Device Tracking for Snapchat Ads on Shopify

Following user journeys across multiple devices. Here's how this applies specifically to Snapchat Ads advertising and why causal inference gives you a clearer picture than Snapchat Ads's own reporting.

What is Cross-Device Tracking?

Following user journeys across multiple devices. For Shopify brands running Snapchat Ads campaigns, understanding this concept is critical because it directly impacts how you evaluate Snapchat Ads's contribution to your revenue.

Cross-Device Tracking	Snapchat Ads reports	Causal truth
Data source	Snapchat Ads Ads Manager	GA4 + Shopify (independent)
Methodology	Click/view tracking	Causal inference
Bias	Self-serving (overcredits Snapchat Ads)	Independent (no platform bias)

Why Snapchat Ads's view of cross-device tracking is misleading

Snapchat is a top-of-funnel awareness channel — Gen Z discovers on Snap, researches on Google, buys on your site
Snap's attribution window is short (1-day view, 28-day click) and misses the full journey
Last-click credits Google Shopping or Meta retargeting for purchases that Snapchat initiated

How causal inference measures cross-device tracking for Snapchat Ads

Causal inference measures Snapchat's downstream revenue impact — even when the purchase happens on Google
No dependency on Snap Pixel — immune to app-to-web tracking gaps
Shapley values fairly credit Snapchat's role in the discovery → research → purchase chain