For vacation rental businesses using HubSpot CRM, capturing the Google Analytics Client ID creates a powerful connection between anonymous website behavior and identified contacts.

What is the Client ID?

The GA Client ID is a unique identifier assigned to each visitor. By capturing this in HubSpot, you can connect a contact's entire website history to their CRM record.

This enables you to answer questions like:

Which blog posts did this lead read before booking?
What was their first touchpoint with our brand?
How many times did they visit before converting?

Implementation Steps

Step 1: Form Setup

Create form fields (visible or hidden) to receive Client ID data. Hidden fields work best for seamless user experience.

Step 2: Variable Creation

Use Google Tag Manager's Custom JavaScript to extract the Client ID:

function() {
  return ga.getAll()[0].get('clientId');
}

Step 3: Form Population

Insert a custom HTML tag that assigns the captured ID to designated form fields. This fires before form submission to ensure the data is included.

Step 4: Trigger Configuration

Set Page View triggers (Window Loaded) to fire on specific pages containing forms. This ensures the Client ID is captured as soon as possible.

Step 5: HubSpot Integration

Create custom contact properties in HubSpot matching form field names for automatic data synchronization:

Property name: ga_client_id
Field type: Single-line text
Auto-population: From form field

Using the Data

Once captured, you can:

Send to advertising platforms - Upload as offline conversions to Google Ads, Facebook
Build segments - Create lists based on website behavior patterns
Personalize outreach - Reference pages they visited in your emails
Attribution reporting - Connect revenue to original traffic sources

Marketing Attribution Benefits

With Client ID capture, you can trace every booking back to the original marketing touchpoint—whether that was a Google ad, organic search, or social media post weeks or months ago.

This level of attribution helps you:

Optimize marketing spend across channels
Understand the true customer journey
Calculate accurate ROI for each campaign
Make data-driven budget decisions

Additional Resources

Check out the video tutorial for a step-by-step walkthrough of the implementation.

Credit to Mixed Analytics for the implementation code referenced in this guide.