The key to this is creating a robust tracking foundation that connects your ad clicks to the final app install, even though the user journey spans multiple platforms.
Here are the core steps and best practices:
A. The Base Tag (Global Site Tag)
B. The Primary Conversion Action (The App Install)
The most important conversion action for you is an app install. This is where the tracking can get tricky because the user leaves your website and goes to the Shopify App Store.
Best Practice: The most reliable way to track this is to use server-side tracking (Conversions API) or to set up a "Thank You" page after the install.
Ideal Method: If the Shopify App Store allows you to redirect a user back to a specific URL on your website after they install the app, set up a page like yourdomain.com/thank-you. This "Thank You" page should fire a Google Ads conversion tag (set up in GTM) specifically for an "App Install" or "New Customer" conversion action.
Alternative: If a redirect is not possible, you may need to rely on tracking the "Visit to App Store" click as a micro-conversion.
C. Micro-Conversions
These are actions that indicate a user is highly interested but hasn't installed yet. Tracking these helps the Google Ads algorithm learn what a high-quality user looks like.
Examples:
Clicking the "View App Listing" or "Install" button on your website.
Submitting a contact form or demo request.
Spending more than X minutes on a specific page.
Action: Set up these micro-conversions in Google Ads and implement them on your website using GTM. You can set them to have a lower value than a primary conversion.