💡 What is subdomain traffic performance analysis?
Many businesses use a subdomain (like event.website.com or blog.website.com) to run marketing promos or publish content, with the goal of driving traffic to their main website or e-commerce site (www.website.com). Subdomain traffic performance analysis exists to help you precisely measure how many users these subpages successfully drive to your core conversion pages.
Feversocial's page service lets customers easily build promo pages hosted on a subdomain (like a holiday-themed page). You can use specific GA4 features to track the real traffic value those promo pages generate.
✨ Two core principles for tracking subdomain traffic
UTM should only be used for tracking traffic from outside your site:
GA treats a subdomain and the main domain as the same domain. Because of this, never add UTM parameters to links between pages on the same subdomain to track internal traffic.
The risk of misusing UTM: if a user arrives at your subdomain from an external ad carrying one set of UTM parameters, then clicks a link on that subdomain page carrying a different set of UTM parameters, GA will overwrite the user's original source/medium midway through their journey. This means your final conversion data (like an e-commerce purchase) can no longer be traced back to the original LINE push or paid ad source — seriously polluting your data.
Your subdomain and main domain must share the same GA4 ID:
Make sure every subdomain you use (like event.website.com) shares the same GA4/Measurement ID as your main domain (like www.website.com).
Only when you use a single ID can GA4 treat a user's behavior across different domains as one continuous user journey, giving you the complete picture of their traffic path.
📊 How do you track traffic your subdomain sends to your main site?
GA4 is an event-based analytics system that offers a high degree of flexibility, letting you customize reports across many dimensions.
To analyze how effectively your subdomain drives traffic to your main site, we recommend using these two GA4 Explore report techniques instead of on-site UTM tracking:
Tracking method | Purpose | Related guide |
GA4 Funnel Exploration report | Tracks the path flow and drop-off rate from your subdomain (like /event/) to a target page on your main site (like /shop/). | See guide: GA4 | Funnel Exploration Report Setup Guide |
GA4 Page Click Performance Exploration report | Tracks the actual number of clicks from a specific source page A to a specific target B. |
🛠️ GA4 | Subdomain Traffic Performance Setup Guide
Since the best way to analyze subdomain traffic performance is through GA4's Explore reports, here's a detailed setup guide — pick the article that matches your needs.
Goal A: Analyze the cross-page flow and drop-off rate
If you want to know how many users entered through your subdomain page (like /event/) and successfully continued on to your core service or product page (like /tw/) as intended, use the "Funnel Exploration report."
Tip: when setting up each step, use the page location dimension to define your subdomain or a specific group of pages.
[Image: GA4 Funnel Exploration report setup interface, highlighting the step definition area]
Goal B: Analyze the number of clicks on a specific element
If you want to precisely measure how many users on your subdomain promo page clicked a specific button or link through to your main site or e-commerce site, use the "Page Click Performance custom report."
Tip: use the fever_page_click event that Feversocial fires, and use the Link URL and page location filters to specify the source and target.
[Image: GA4 Free Form Exploration report setup interface, highlighting the filters section]