Enhanced Conversions and Advanced Matching: How First-Party Data Recovers Lost Ad Conversions
Click IDs aren’t always reliable, especially on Safari and iOS. Enhanced Conversions (Google) and Advanced Matching (Meta) use hashed first-party data to fill the gap, recovering 5–33% more conversions.
Every ad platform needs to answer the same question: did this ad click lead to a conversion? The primary way they do that is by matching a Click ID (like Google’s gclid or Meta’s fbclid) from the original ad click to the conversion event sent back later.
The problem is that Click IDs aren’t always reliable. Safari’s Intelligent Tracking Prevention caps client-side cookies at 24 hours after a decorated ad click. iOS Private Browsing strips Click IDs from URLs entirely. Ad blockers prevent tracking scripts from firing. And users who switch devices between clicking an ad and converting leave no Click ID trail at all.
When the Click ID is missing or expired, the ad platform can’t attribute the conversion. You paid for the click, the user converted, but the platform never finds out, so its algorithms can’t learn from it.
Enhanced Conversions and Advanced Matching solve this by giving ad platforms a second way to match conversions back to clicks: hashed first-party customer data.
What are Enhanced Conversions and Advanced Matching?
These are features from Google and Meta respectively, but they solve the same problem in the same way.
Google Enhanced Conversions supplements your existing conversion tags by sending hashed first-party customer data (email address and phone number) alongside the conversion event. Google matches this data against signed-in Google users to attribute conversions that the Click ID alone couldn’t.
Meta Advanced Matching does the same thing for Facebook and Instagram ads. When you send conversion events through the Meta Pixel or Conversions API, you include hashed customer data (email, phone, name, date of birth, location, etc.). Meta matches this against its user base to attribute conversions where the fbclid was lost or unavailable.
In both cases, the customer data is SHA-256 hashed before it leaves your server. The ad platforms never see the raw values. They use the hashes to find a match in their own user database and attribute the conversion to the original ad click.
Why Click IDs alone aren’t enough
Click IDs were designed to be the definitive link between an ad click and a conversion. But several forces have made them unreliable:
Safari ITP restricts cookie storage. When a user clicks an ad and lands on your site, the Click ID is typically stored in a JavaScript cookie. Safari’s Intelligent Tracking Prevention caps these cookies at 24 hours when the navigation comes from a classified tracking domain with URL parameters. If the user converts after that window, the Click ID is gone.
Private Browsing strips Click IDs. Safari 26 (iOS 26) strips gclid, fbclid, msclkid, and other tracking parameters from URLs in Private Browsing mode, Mail, and Messages. The Click ID never reaches your site in the first place.
Cross-device journeys break the chain. A user clicks your ad on their phone during lunch and completes the purchase on their laptop that evening. The Click ID on the phone never transfers to the laptop, so the conversion can’t be matched by Click ID alone.
Ad blockers prevent the script from running. If an ad blocker prevents your tracking script from executing, the Click ID is never captured from the URL, even if it’s present.
The result is that a meaningful percentage of your actual conversions can’t be attributed through Click IDs. Enhanced Conversions and Advanced Matching recover those lost attributions by using a different matching signal, one that persists across devices, browsers, and sessions.
The numbers: how much do they recover?
Both platforms have published the data.
Google Enhanced Conversions
Google conservatively states a 5% increase in conversions on Search campaigns when Enhanced Conversions are enabled. That’s Google’s own benchmark, intentionally understated.
Independent tests tell a more compelling story. Independent case studies show 16–33% increases in measured conversions after implementing Enhanced Conversions, with the variation depending on how much of their traffic comes from Safari/iOS, the length of their conversion window, and how many users switch devices.
The improvement comes from conversions that were actually happening all along. Enhanced Conversions makes them visible to Google’s bidding algorithms. Smart Bidding suddenly has more signal to optimize against, leading to better targeting and lower CPAs.
Meta Advanced Matching
Meta reports that advertisers using Advanced Matching see an average 8% increase in matched purchases, with many experiencing double-digit improvements.
In one notable case, one of the world’s largest meal-kit companies saw a 27% increase in attributed conversions after enabling Advanced Matching. These weren’t new customers. They were existing conversions that Meta’s systems couldn’t previously match to an ad click.
For Meta specifically, the increase in matched events also improves Custom Audience targeting and Lookalike Audience quality. When Meta can see more of your actual converters, it builds better models of who to target next.
How Enhanced Conversions and Advanced Matching work
The implementation follows the same pattern on both platforms:
1. Collect first-party customer data at conversion
When a user completes a conversion (purchase, sign-up, form submission, etc.), you capture the customer data they’ve provided: email address, phone number, name, and any other identifiers the platform supports.
2. Hash the data before sending
The data is hashed using SHA-256 before it’s transmitted. This is a one-way hash. The ad platform can’t reverse it to see the original values. Both Google and Meta require specific formatting (lowercase, trimmed whitespace) before hashing to ensure consistent matching.
3. Send hashed data with the conversion event
The hashed customer data is included alongside the conversion event, either through:
- Google: Enhanced Conversions for Web (via gtag or Google Tag Manager) or Enhanced Conversions for Leads (via server-side upload)
- Meta: The Meta Pixel (client-side) or Conversions API (server-side)
4. The platform matches against its user base
Google matches the hashed data against signed-in Google accounts. Meta matches against its user database. When a match is found, the conversion is attributed to the original ad click, even if the Click ID was missing.
Server-side is the stronger implementation
Both platforms support client-side and server-side implementations, but server-side consistently performs better:
Client-side (pixel/tag-based): The hashing and sending happens in the browser. This is simpler to set up but vulnerable to ad blockers, Safari ITP restrictions, and JavaScript errors. If the script is blocked, no data gets sent.
Server-side (Conversions API): The hashing and sending happens on your server. Ad blockers can’t interfere. Safari ITP doesn’t apply. The data is more reliable, more complete, and reaches the ad platform every time.
Both Google and Meta recommend running server-side alongside client-side for maximum coverage. Meta specifically reports that advertisers using the Conversions API with the pixel see a 13% lower cost per result compared to pixel-only implementations.
How Aetra automates this for Segment users
If you’re using Segment, Aetra handles Enhanced Conversions and Advanced Matching automatically as a native destination:
Automatic first-party data collection. Aetra collects matching parameters (email, phone, and other identifiers) from your existing Segment page, identify, and track events. No additional instrumentation needed.
Click ID capture . Aetra automatically captures Click IDs (gclid, fbclid, etc.) server-side, so every conversion event includes both the Click ID (when available) and first-party matching data. This gives ad platforms two ways to match every conversion, maximizing your match rate.
Identity resolution across sessions. When an anonymous visitor clicks an ad and later identifies themselves (sign-up, purchase, form fill), Aetra links the original click data to their profile. This recovers cross-session and cross-device conversions that neither Click IDs nor client-side matching can capture.
Event enrichment before delivery. Every conversion event flowing through Segment gets enriched with both click data and matching parameters before it reaches Google, Meta, or any other ad platform destination. The enrichment happens server-side. Ad blockers and ITP can’t interfere.
90-day data retention. Aetra stores attribution data for 90 days, covering the long conversion windows common in B2B sales cycles. Even if a user clicks your ad in January and converts in March, the data is there.
The result: you get the full benefit of Enhanced Conversions and Advanced Matching without manually implementing each platform’s API or maintaining separate data pipelines.
After setting up Aetra, we doubled orders in Google Ads and saw a 36% increase in leads on Facebook
Stefan Harvalias, CMO, Tawkify
Getting started
If you’re running Google or Meta ads and haven’t implemented Enhanced Conversions or Advanced Matching, you’re leaving conversions on the table, conversions you already paid to acquire.
For Segment users, Aetra handles the implementation automatically. For everyone else, both Google and Meta provide documentation for manual setup, though the server-side implementations require more engineering work.
Either way, the data speaks for itself: 5–33% more conversions from Google, 8–27% more from Meta, and lower CPAs across the board. These are conversions that are already happening. You just need to make them visible.
Schedule a demo to see how Aetra enriches your Segment events with first-party matching data and watch your match rates climb.
Engineer turned marketer with 10+ years in ad tech and marketing technology. Obsessed with closing the gap between ad spend and accurate attribution.