My Real-World GTM Implementation
For a B2B software client, I encountered a challenging situation: they needed to track demo requests that occurred through multiple paths on their website. These paths included a header button, an inline form, and a popup modal. Each used different code and submitted to different endpoints.
Rather than creating three separate conversion tags, I used GTM to:
- Set up a single Google Ads conversion action for “Demo Request”
- Created a custom GTM trigger that fired on form submissions from any of the three sources
- Added a data layer event to capture lead quality information
- Implemented a custom variable to pass the lead’s industry as a conversion parameter
This approach not only simplified tracking but also provided richer data about which industries responded best to different ad messages. This is information that proved invaluable for campaign optimization.
After implementation, we tested thoroughly using GTM‘s Preview mode to ensure every conversion path correctly fired the tag. This revealed an unexpected issue: the popup form submissions weren’t triggering our conversion because they used a different success indicator than the other forms. After fixing this discrepancy, we finally had complete, accurate tracking across all conversion points.
For ongoing management of such complex setups, resources like the Optimize Smart Conversion Checklist have been invaluable to me.
Avoiding Duplicate Conversions: Lessons from My Mistakes
Early in my Google Ads career, I made a costly error that taught me the importance of preventing duplicate conversions. For a client selling online courses, I set up Google ads conversion tracking on their “thank you” page, not realizing that students frequently revisited this page to access course materials. The result was massively inflated conversion numbers that made the campaigns look far more successful than they truly were.
How to Prevent Duplicate Conversions
I now religiously use transaction IDs when setting up ecommerce tracking. For a recent retail client, I implemented conversion tracking that included:
- A unique transaction ID for each order (their order number)
- The dynamic conversion value (order total)
- Custom parameters for product category and new vs. returning customer status
This approach ensures that even if a customer views their order confirmation multiple times (or across multiple devices), Google Ads counts it as just one conversion. For this particular client, implementing transaction IDs reduced their reported conversions by 23%. This number revealed that nearly a quarter of their “conversions” had been duplicates!
For lead generation clients, I typically set the conversion counting method to “One” rather than “Every,” ensuring each lead is counted only once per ad click. However, for specific actions that genuinely should be counted multiple times (like appointment bookings for a medical practice), I use “Every” with careful monitoring for unusual patterns.
I perform monthly audits for all my clients, comparing Google Ads conversion data against their CRM or sales records to catch any discrepancies early. During one such audit for a financial services client, I discovered their form was submitting twice when users clicked the button twice. This led to creating duplicate leads. By adding a simple JavaScript fix to disable the button after the first click, we eliminated the issue and gained more accurate conversion data.