Meta Conversions API: measure your sales when the pixel no longer sees everything

Your Ads Manager doesn't show the same number of purchases as your store. Or it counts every click on “Order” as a “purchase,” while some cash-on-delivery packages come back refused. Either way, Meta is optimizing your campaigns on bad data. The Conversions API fixes part of the problem. Here's why the pixel alone is no longer enough, how to set it up, and how to adapt it to cash on delivery and WhatsApp orders.

Why isn't the Meta Pixel enough on its own anymore?

The pixel is a snippet of code that runs in the visitor's browser (see our guide The Meta Pixel: what it is and how to install it). So anything that gets in the browser's way gets in the pixel's way:

• Ad blockers. Shopify's Help Center says it plainly: a browser-side blocker can stop the Meta Pixel from sharing data, while data sent server to server can't be blocked by those blockers.
• Safari. Since 2019, Safari has capped the lifetime of cookies created by JavaScript at seven days, according to the WebKit blog. A visitor who comes back to buy ten days later may no longer be recognized.
• iOS. Since iOS 14.5, in April 2021, apps must ask permission before tracking a user across other companies' apps and websites, according to Apple. This limits what Meta can connect between its apps and your website.
• The network. Meta acknowledges that the pixel can lose events because of connection problems or page-loading errors (Meta's best practices). On a patchy 4G connection, the thank-you page doesn't always load.

What is the Conversions API, in practice?

It's a direct channel between your server, or your e-commerce platform, and Meta. Instead of waiting for the customer's browser to send “Purchase,” your system sends it, once the order is recorded.

Meta recommends using it in addition to the pixel and sending the same events through both channels (Meta). Each server event contains:

• a name — Purchase, Lead, AddToCart, or a custom name;
• the time it happened, which can be no more than seven days before it is sent, according to Meta's documentation;
• a source: website, app, phone, store, messaging…;
• a unique ID, for example the order number;
• customer information, hashed, such as email and phone number, which helps Meta connect the purchase to the person who saw the ad.

How do you set up the Conversions API on your website?

Meta also says that an advertiser who already has a pixel and only sends web events can turn on the Conversions API from Events Manager, without hosting anything. We found no official list of the countries where this applies: check whether the option shows up in your account. And if your website needs rebuilding, build tracking in from the design stage, as in our website design service.

How do you avoid counting the same sale twice?

If the pixel and your server both send “Purchase” for the same order, Meta needs to know it's the same one. That's deduplication. The rule, according to Meta's documentation:

• the event name is identical on both sides;
• the ID sent by the pixel (eventID) is identical to the server's (event_id);
• both reach the same pixel, less than 48 hours apart.

The simplest approach: use the order number as the ID, on both sides. Meta also accepts a method based on the event name and the fbp or external_id identifiers, but it generally only works if the browser event arrives first.

How do you improve event match quality?

In Events Manager, Meta scores the match quality of your server events out of 10: it shows how well your customer information lets it connect the event to an account (Meta). To raise it:

• Send email and phone number, hashed. Meta lists email, phone number, IP address, first name and last name among the high-quality parameters.
• Format Moroccan numbers. Meta asks you to include the country code and strip out symbols and the leading zero (Meta's rules): 06 12 34 56 78 becomes 212612345678 before hashing.
• Pass fbc and fbp, the Meta identifiers stored in the browser, without hashing them.
• Add an external_id, your customer ID, in the same format everywhere.

Cash on delivery and WhatsApp: what should you send to Meta?

This is where the Conversions API becomes truly useful in Morocco. The pixel sees a click on “Order.” It doesn't see the confirmation call, the refused package or the cash handed to the courier.

For cash on delivery

• Keep the purchase event at the moment of the order: it's the fast signal Meta learns from.
• Also send, from your back office, a custom server event when the order is delivered and paid, for example “DeliveredOrder,” with the order number and the amount collected.
• Create a custom conversion on this event to see, campaign by campaign, how many orders actually end up paid.
• Send it within seven days of delivery, or Meta will reject it.

For WhatsApp orders

Meta offers a Conversions API dedicated to messaging. It reports events such as Purchase, LeadSubmitted or OrderDelivered from conversations started by an ad that clicks through to WhatsApp, Messenger or Instagram, and lets you optimize click-to-WhatsApp ads for purchases, according to Meta's documentation. Three limits:

• it goes through the WhatsApp API (Cloud API), usually via a partner: the WhatsApp Business app on its own isn't among the documented options;
• matching on hashed data, without a click ID, is only open in certain countries, and Morocco isn't confirmed among them;
• Meta doesn't deduplicate these events: it's up to you or your partner to do it.

To set up selling on WhatsApp in the first place, see our guide WhatsApp Business for selling in Morocco.

One last point: collecting and passing on a customer's phone number or email is processing of personal data. Law 09-08 requires the person's consent (Article 4) and regulates transfers abroad (Articles 43 and 44). Update your privacy policy and have the setup approved by your legal counsel.

Sources

• Meta — Conversions API best practices ; deduplication ; server event parameters ; customer information ; Conversions API Gateway ; Conversions API for messaging.
• Shopify Help Center — Facebook data sharing.
• WooCommerce — Meta for WooCommerce.
• WebKit — Intelligent Tracking Prevention 2.1, February 21, 2019.
• Apple Newsroom — iOS 14.5, April 26, 2021.
• Law No. 09-08 on personal data, Articles 4, 43 and 44.