Case Study: How to Track Conversions from Email Campaigns Back to Facebook Using CAPI

[btaliat]

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Hey folks!


If you're running lead generation campaigns through Facebook and following up with email marketing, this one’s for you.


A lot of marketers are missing out on an important optimization step: connecting email-driven conversions back to Facebook. When that data loop is broken, you’re not giving the algorithm the insights it needs to deliver better traffic.


This case study walks you through how we improved performance and attribution for a simple two-part funnel: Facebook Ads ➝ Lead Capture ➝ Email Follow-up ➝ Affiliate Offer. With a few adjustments and the right setup, we were able to send conversion data back to Facebook via CAPI (Conversions API), allowing for better campaign optimization — even though the actual conversion happened through email, not a direct Facebook click.


Let’s break it down step by step.

Step 1: The Lead Capture Campaign​

Our starting point was a Facebook Ads campaign that drove users to a lead capture page.


Main Goal: Collect email addresses.


Here’s what was set up:

• A landing page that captured user emails.
• A tracking platform that created a dedicated campaign to manage this flow.
• A Facebook CAPI connection prepared from the beginning, even though the conversions were going to happen later.

Each lead captured was tied to a unique click ID. This would be important for tracking later on.

Step 2: The Email Follow-Up Campaign​

After leads were collected, we moved on to the second part: sending promotional emails.


Main Goal: Get users to click through and convert on affiliate offers.


Here’s what was implemented:

• A new campaign was created specifically for email traffic.
• Each email included tracking links that passed the original click ID (or subscriber ID).
• When users clicked and converted on the affiliate offer, that conversion was logged in our tracker.

The important part was tying this conversion back to the original lead generation campaign. We didn’t just track that someone converted — we wanted to know which Facebook ad originally brought them in.

Step 3: Bridging the Two Campaigns​

This is where it gets technical — but also where the magic happens.


The goal here was to send the conversion event back to Facebook, even though it came from an email click. That meant linking both campaigns together and passing information accurately.


We achieved this by:

• Creating a connection between the lead gen campaign and the email campaign in the tracker.
• When a conversion happened via the email, we triggered a postback URL tied to the lead generation click.
• This conversion event was then pushed back to Facebook via CAPI, with all relevant parameters (user data, click ID, timestamp, etc.).

This setup ensured that Facebook received credit for the conversion, even though it happened after the initial ad click, and through a different channel (email).

Results & Benefits​

Once this connection was in place, we saw:

• Better optimization from Facebook: Because it was receiving accurate conversion data, the algorithm began serving ads to higher quality leads.
• Improved ROAS: The campaign began to attract leads who were more likely to engage with emails and ultimately convert.
• Cleaner reporting: No more guessing where the conversions came from — every step in the journey was tracked and attributed correctly.

Takeaways for Affiliate Marketers & Lead Gen Pros​

1. Don’t ignore email conversions: Just because the sale doesn’t happen on the landing page doesn’t mean you shouldn’t track it back to the source.
2. Use tracking tools wisely: Platforms that allow you to tie multiple campaigns together are worth their weight in gold.
3. Facebook CAPI is underutilized: If you're not sending conversions back via API, you’re leaving optimization power on the table.
4. Build your data pipeline from Day 1: Prepare your tracking, IDs, and event setup before launching your campaigns — not after.

That’s it! With a simple setup like this, you're no longer flying blind. Instead, you’re feeding Facebook what it needs to optimize, even if your funnel is multi-step and includes email sequences.


Let me know if you'd like a deeper dive into the postback setup or how we structured the actual email sequences. Happy to share more insights!