Stepping Into The New World of Tracking With cAPI 

When people come onto your website, your server grabs the content, their browser (known in technical terms as their client) loads the content. Server side and client side. 

For the past 20 years, server side and client side have worked happily together in a sharing caring relationship. But in the past few years, it’s all got a bit one-sided. Client sided specifically. In the past browsers loaded cookies and those cookies shared data that got picked up by various systems and passed back to you, the business owner, but the client side is starting to be a bit selfish and not share as much as it used to. 

Rather than sitting around and accepting this selfish streak, the server side is starting to fight back by cutting out the client side and figuring things out itself. There are a few systems out there already doing this, but the one most people are familiar with is Meta’s cAPI, so that’s what we’re going to focus on. 

How Does cAPI Work? 

cAPI works by sending data that occurs on your site directly to the Facebook servers, where it’s used to track conversions and build custom audiences. It cuts out the client side and no longer needs cookies to track. 

However, it’s not perfect. Cookies are much better at identifying individual users and connecting the dots between clicking or viewing an ad and making an action on site. As a result, both cookies and cAPI try and achieve the same thing, but they both miss some of the actions that we want them to track. 

The landscape looks like this: 

If you just use Meta’s pixel, you miss a lot of conversions. If you just use cAPI, you still miss a lot. But if you use both, you capture much more of the overall number of conversions your ads are generating. Any in the middle that are picked up by both are de-duplicated if everything is set up correctly but do check this, I’ve now seen 3 sites where the same conversions were tracked by both methods and recorded as separate conversions. 

Right now, or in the past depending on when you’re reading this, cAPI has given some incremental tracking but most of the trackable conversions were already picked up by the pixel. The problem is that increasingly we’re moving to a world that looks like this:


Meta’s pixel and cAPI are struggling to track due to pressure from privacy laws, private browsing, cookie refusal and the increasing complexity of making all these systems work effectively. However, the ability of the pixel to track is declining at an alarming rate. 

If you have cAPI and Pixel, you’re probably not seeing much loss in your data. If you’re only using Pixel, you are probably starting to notice a significant discrepancy between your ad account data and your actual conversion levels. 

The solution is simple, with 2 parts. 

First, install cAPI as a priority. It’s not easy, you’ve been warned, but it is essential. Maybe you don’t see it as essential right now, but those who move on this now will suffer less as the pixel continues to drop off. 

Second, get comfortable with less data. The cost per sale/lead/conversion your ads report will be different from the real data, it’s useful to tell you when one campaign, ad or audience is doing better than another, but it’s no longer sufficient to tell you the total performance of your campaigns. Use multiple methods, track your overall sales, and compare multiple sources to figure out the true picture. 

For those spending more than a few thousand pounds a month on advertising we can even work with you to run an offline analysis that uses advanced statistical modeling to give an unbiased view on what’s really leading to sales, just chat to our team to find out if this is a good fit for your business. 

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