Using One GA Measurement ID for Main Domains and Subdomains: Pros, Cons, and Recommendations
Navigating the world of Google Analytics (GA) can be a daunting task, especially when it comes to deciding how to set up tracking for your main domain and its subdomains. Should you use the same Measurement ID for both, or is it better to separate them? Let's delve into the considerations to help you make an informed decision.
Advantages of Using the Same Measurement ID:
Unified Reporting: By using a single Measurement ID, all data from your main domain and subdomains will be housed in one property. This centralized approach allows for a clearer view of aggregate data, such as total sessions, users, and pageviews across all domains.
Cross-Domain Tracking: A seamless user experience is crucial. When users navigate between your main domain and subdomains within a single session, the same Measurement ID ensures their journey is tracked without initiating a new session upon domain switches.
Simplified Setup: With one Measurement ID, you're only managing one property and one set of tracking code, streamlining the process.
Data Granularity: High traffic volumes can muddy the waters. Differentiating between main domain and subdomain traffic might require filters or advanced segments to maintain clarity.
Potential for Data Contamination: A single tracking issue on one domain (like spam or bot traffic) can compromise the data quality across the entire property.
Limited Customization: Diverse tracking needs between the main domain and subdomains (such as different events or goals) can complicate management within a single property.
Use Views: If you opt for a single Measurement ID, diversify your views within your GA property. Create an unfiltered view for all data, a main domain-only view, and a subdomain-only view. This structure facilitates both combined and separate data analysis.
Setup Cross-Domain Tracking: Ensure that cross-domain tracking is correctly set up to provide a smooth tracking experience as users navigate between the main domain and subdomains.
Embrace Google Analytics 4 (GA4): If you're in the process of setting up a new property, GA4 is worth considering. Compared to Universal Analytics, GA4 offers enhanced flexibility in tracking and reporting. It's adept at tracking multiple domains and subdomains, providing diverse ways to analyze data.
The decision to use the same Measurement ID for both your main domain and its subdomains hinges on your specific needs. If a unified view and a streamlined setup appeal to you, then it's a viable option. However, if your focus leans towards granularity and customization, it might be worth exploring separate Measurement IDs or the advanced capabilities of GA4.