Phase 1: Foundation (Weeks 1-2)

5.1 Define Your Conversion Events

Before building anything in GTM, map your business conversions.

Identify Your Key Conversions

For E-commerce:

• Purchase (your primary revenue event)
• Add to Cart (early funnel signal)
• Product Page View (intent signal)
• Initiate Checkout (abandonment risk)

For SaaS:

• Free Trial Signup
• Demo Request
• Upgrade / Purchase
• Feature Usage

For Lead Gen:

• Form Submission
• Phone Call
• Chat Inquiry

Create Your Conversion Roadmap

Make a simple table:

Conversion Event	When It Fires	Why It Matters	Where It Goes
Purchase	Order confirmation page	Revenue tracking, main optimization event	Meta, Google Ads, Analytics
AddToCart	User clicks "Add to Cart"	Early funnel signal for optimization	Meta, Google Ads
ViewContent	Product page loads	Product interest signal	Meta, Google Ads
Lead	Form submitted	Qualified prospect	Google Ads, HubSpot CRM

Pro tip: Start with 3-5 core conversions. Don't track 20 events at launch. Master the basics first, then expand.

5.2 Map Your Customer Data

What customer information do you need to send to ad platforms for audience building and optimization?

First-Party Data You Should Capture

Data Point	Example	Why You Need It
Email	[e-mail]	Matching with platform audiences, CRM sync
Phone	[phone]	Phone match audiences, customer identification
Location (City, State, Country)	San Francisco, CA, US	Geo-targeting, regional campaign optimization
Customer Status	New / Returning	Segment audiences, optimize for new vs. repeat
Purchase History	Lifetime value, products bought	High-value customer targeting, recommendations
Company (B2B)	Acme Corp	Account-based marketing

When/Where to Capture

• At checkout - You always have customer data here
• On signup/login - Email and name available
• On form submission - If you collect data
• From CRM - If customer is already in your system

Privacy first: Only collect and send data users have consented to. This is essential for GDPR and CCPA compliance.

5.3 Align With Your IT/Dev Team

Share the conversion roadmap and data map with your technical team. They need to confirm:

• "Can you track these conversions in the data layer?"
• "Can you push customer data to the data layer at these touchpoints?"
• "Do we have a CRM/system to flag consent status?"