Sending Smarter Signals with Conversion APIs

If you’re running ads today, you've felt it already. Tracking has changed. Traditional signals are no longer as reliable as they used to be, and that puts real pressure on marketers to get smarter about how data is collected, interpreted, and activated.

The core challenge is no longer whether you have tracking in place, but whether you can still trust what your platforms are learning from it.

In a privacy-first world, the question becomes simple — and uncomfortable: How do you keep your campaigns measurable when browser-based tracking keeps breaking down?

Conversion APIs

Conversion APIs were introduced as a response to growing signal loss. Cookie deprecation, browser restrictions, ad blockers, and tightening privacy regulations have all made client-side tracking unreliable. Events get delayed, dropped, or never delivered at all.

Conversion APIs change the transport layer. Instead of sending signals through the browser, conversion data is sent directly from your system to the ad platform — server to server. No browser. No blockers. No guesswork.

But while the delivery mechanism improved, the data strategy often didn’t.

A common mistake is treating Conversion APIs as a checkbox.

✔︎ We turned on CAPI for Meta.
✔︎ We added a server-side tag for Google.

However, if the underlying data is inaccurate, you’ve simply moved bad data from the browser to the server. The signal is cleaner technically, but still misleading strategically.

RetentionX's conversion tracking, identity resolution, and conversion APIs are built to solve that problem.

How it Works

One of the biggest challenges with Conversion APIs is fragmentation. Each platform has its own logic, its own definitions, and its own incentives. Without a unifying layer, you end up with competing stories about performance when checking your ERP vs. ad platform vs conversion tracking.

RetentionX solves this by acting as the orchestration layer. 

A robust Conversion API setup starts with a single source of truth. In RetentionX, that source is always your store. Purchases, refunds, cancellations, and subscription events are taken directly from your eCommerce platform; not inferred from browser behavior.

From there, events are enriched before they ever reach an ad platform. RetentionX adds identity context (who the customer is), product-level detail (what was purchased), and economic context (how valuable that purchase really was, based on margin rather than just revenue).

Only after this enrichment step does RetentionX send events server-to-server to platforms like Meta, Google, or TikTok. This ensures that every conversion is clean, deduplicated, and aligned with your actual business reality.

The result is a conversion setup that allows you to reconcile what platforms report with what actually cleared in your backend, avoid double-counting when browser and server events overlap, and build a realistic view of CAC, payback, and performance per channel.

Setting up Conversion APIs

Before you begin, make sure the RX tracking pixel is implemented and active. Conversion APIs can only be configured once the pixel is running.

1. In RetentionX, go to Automation → Conversion APIs.

2. Click New API to create a setup from scratch. If you prefer, select one of the available templates that come preconfigured with RetentionX best practices and recommendations.
   
   
    

3. Select the Event Trigger you want to send to a third-party platform. This defines when RetentionX should push an event, for example when a purchase occurs.

4. Enter an Event Name. This is the name that will appear inside the destination platform, such as Meta or Google.
   
   
    

5. Select the Destination Platform you want to push the event to. If the platform isn’t connected yet, RetentionX will prompt you to connect it during this step.
   
   
    

Controlling Which Conversions Are Sent

Not every conversion should be treated equally. Conversion APIs become truly powerful when you control which conversions are pushed to third-party platforms.

In RetentionX, you can apply filters to specify which events should be sent. This allows you to push only certain types of orders, such as subscription purchases, high-margin orders, or conversions from specific customer segments. You can also exclude orders that are heavily discounted or do not meet your quality criteria.

By filtering conversions before they reach an ad platform, you ensure that optimization is based on meaningful business outcomes rather than raw volume.

For your paid ads, these conversion events are a powerful signal to evaluate and improve campaign performance-- each time an event is triggered (e.g. a purchase), Meta receives a confirmation. These signals can be used to optimize your campaigns (e.g. focusing on high-value purchases) or simply to monitor conversion volume and understand which campaigns are driving results.

Below is an overview of the events that can be sent via Conversion APIs and the filters available for each event type.

Using Conversion Events in Third-Party Tools

Once Conversion API events are sent to a marketing platform, they can be used in two different ways. They can either serve as:

• optimization events or 

• as analytical signals.

When used as optimization events, conversions directly influence bidding and delivery. Platforms receive a confirmation each time an event is triggered and use this information to optimize campaigns. For example, campaigns can be optimized toward high-margin purchases or new customers only. 

Alternatively, conversion events can be used purely for analysis. In this case, they provide visibility into conversion quality and campaign performance without impacting bidding. This is useful for monitoring results, comparing campaigns, or testing new signals before using them for optimization. For example, you might optimize campaigns for purchases, while using additional conversion events to understand how many of those purchases included a subscription versus one-time purchases.

Once conversions are defined and filtered in RetentionX, you are no longer limited to generic success signals like “a purchase happened.” You can define what success actually looks like for your business.

Instead of optimizing on revenue alone, you can optimize on gross margin. Instead of allowing acquisition campaigns to learn from repeat purchases that would have happened anyway, you can focus on new customers. You can attach customer segments such as VIPs, high-LTV customers or high return-risk profiles to understand which campaigns are creating the customers you actually want more of.

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