In the old days, Google relied on "cookies" to track users. A user clicked an ad, a cookie was saved, and if they bought something later, the cookie told Google.
Today, browsers (Safari, Firefox) delete cookies after 24 hours. If a user clicks today and buys next week, Google has no idea.
The solution? Enhanced Conversions. Instead of relying on a fragile cookie, we send Google something permanent: the user's email address.
But Wait... Is That Safe? (Hashing)
You might be thinking: "I can't just send my customer's private email to Google!"
You are right. You don't send the email. You send a Hash. This is a one-way encryption code (SHA256).
The Result: The "Match Rate" Uplift
When you turn this on, you typically recover 5-10% of lost conversions.
These are people who clicked your ad on their iPhone (blocking cookies) but filled out the form on their Desktop. Cookies can't track cross-device. Emails can.
Tracking
Conversions
How to Set It Up
There are two ways to do this, depending on your tech stack.
- Automatic (Google Tag Manager): In GTM, check the box for "Include user-provided data" in your Google Ads Conversion tag. You will need to create a variable that reads the email from your form field.
- Manual (API): For offline sales, you upload a CSV file of hashed emails back into Google Ads every week (or use Zapier/CRM integration).
Conclusion
First-party data is the new gold.
If you aren't using Enhanced Conversions, you are voluntarily throwing away data that you already own. Turn it on, feed the algorithm, and watch your CPA drop.