The new offline conversion standard: Google Data Manager API

Online marketing is changing rapidly. The rules around privacy are becoming stricter and the technical possibilities to track users via “cookies” are decreasing. For companies, this concretely means that it is becoming more difficult to see exactly what an online ad is delivering. These rather technical changes are already difficult for many to follow, let alone to be ahead of the game. Here is yet another new way of measuring conversions in Google Ads.

5 key takeaways before you begin:

1. The end of third-party cookies in most browsers calls for smarter use of your own customer data.
2. The Google Data Manager API links your CRM or POS system directly and securely to your ads.
3. From now on, steer your budget on actual sales rather than just website visitors.
4. Meet the strictest privacy requirements thanks to secure processing via confidential matching.
5. Save time and avoid errors by moving from manual to real-time automation.

Who is this for?

Basically for anyone who collects online leads instead of making direct webshop sales. Think of companies in the service industry, real estate or automotive and like ourselves at upendo. Someone fills out a contact form on the site, but the real deal is done later by phone, an appointment or a quote.

Until now, Google often thought, “Form completed? Success achieved! But you know that not every request also becomes a paying customer. With this new link, you automatically give that important signal back to Google. This used to be a hassle with manual spreadsheet imports or unstable workarounds via tools like Zapier, but now it can be much easier and more stable.

First-party data as the only stable currency

The ad market is moving irreversibly away from reliance on third-party cookies. Fueled by regulations such as the GDPR and technological barriers such as Apple’s Intelligent Tracking Prevention (ITP), the traditional “glue” that linked ad clicks to purchases is disappearing.

In this new reality, first-party data, the data that companies collect directly from their customers, is the only remaining stable basis for good targeting and attribution. The challenge, however, is not owning this data, but activating it. Many organizations struggle with theActivation Gap: data is trapped in silos such as CRM systems or data warehouses.

Google Data Manager API: the technical architecture

Google’s answer to this is the Data Manager API. Unlike previous methods, which often required manual uploads or complex, custom engineering, this API offers a streamlined pipeline.

The core principle is “write once, use everywhere.” Whereas previously separate integrations were required for Google Ads, Google Analytics 4 (GA4) and Display & Video 360 (DV360), the Data Manager API provides a single point of entry.

• Ingestion: We send a payload of customer data (audience members or conversions) to the API.
• Distribution: The API interprets the configuration and forwards the data to the linked platforms.
• Consistency: This ensures that the same audience definitions are used across all channels.

Confidential Matching & TEEs

One of the most groundbreaking innovations within the Data Manager API is the integration of Confidential Matching into Trusted Execution Environments (TEEs). This has been around since September 2024, but was not yet publicly available. For customers in industries with high compliance requirements, such as healthcare or (semi-)government, this is a game-changer.

Normally, an advertiser must trust that the ad platform is storing the data securely. Confidential Matching changes this trust model by using Confidential Computing:

1. Encryption at the source: The data is encrypted on your server (or through a partner such as Stape).
2. The digital vault (TEE): Data travels encrypted to Google and is only decrypted within a secure area in the server’s processor (the TEE). Code and data in a TEE are invisible to the rest of the system, including Google itself.
3. Attestation: Before sending data, the system verifies that the TEE is authentic.
4. No storage: Only the result of the match (found/not found) leaves the TEE. The raw personal data are never stored in readable form.

This allows us to offer enterprise-level data integrations that are “secure by default.

From operational burden to strategic value

Previously, linking offline data required heavy investment in development and maintenance of complex API versions. The old Google Ads API required in-depth knowledge of specific services. The Data Manager API abstracts this complexity.

Specifically, what does this mean for your marketing strategy?

• Real-time value-based bidding: Instead of managing by numbers of leads, we can now manage by quality of leads. Once a lead gets the status “Approved” in your CRM, we send that signal directly back to Google. The algorithm thus learns to bid on users who actually deliver value.
• Speed: Old CSV uploads often had a delay of 24 to 48 hours. The API processes data in real time.

How upendo implements this

The strength of the Data Manager API is that it allows upendo to hide complexity (“Invisible Complexity”). However, implementation does require specialized knowledge of the Google Cloud Platform (GCP).

We provide the complete technical setup:

1. GCP Configuration: Setting up the Google Cloud Project and API enablement.
2. Authentication: Setting up Service Accounts and secure OAuth 2.0 flows, or integration via server-side Google Tag Manager.
3. Data validation: Ensure correct hashing (SHA256) and normalization of data to maximize match-rates.

At upendo, we like to keep the process simple and transparent. We start with a short meeting to scan your data situation, after which you immediately receive a clear proposal. After agreement, we will arrange the entire technical setup in the Google Cloud and/or other systems; you only need to grant access. Then we won’t let you go: with our monthly checks and active maintenance we ensure that the link remains stable and your campaigns are continuously fed with the right data. Nice and easy!