Launched in response to Apple's privacy-focused iOS 14 update, the Facebook Conversions API (CAPI) is a form of front-end server-side tracking that allows advertisers to more effectively gather user data. It does this by tracking server-side events — basically any user action that leaves a data trail. CAPI essentially allows marketers, advertisers, and brands to collect reliable, accurate, and insightful data about ad performance and user behavior without violating user privacy in the process.
Browser-side tracking, as the name suggests, collects data directly through a user's web browser, typically through the use of a third-party tracking cookie. In addition to behavioral and engagement data, browser-side tracking — also known as client-side tracking — also tends to collect demographic and location data.
Because server-side tracking utilities like CAPI cannot directly access a user's web browser, they do not directly harvest private data. These utilities are thus a viable way of tracking behavior even when a user has disabled third-party cookies and data tracking.Server-side tracking also tends to be more secure than client-side tracking, as data is transmitted directly from the web server to Facebook's servers rather than leveraging the user as a middleman.
Caption: Facebook's CAPI can be invaluable in filling out and contextualizing your Facebook Ad data.
eCommerce is a data-driven field — the more data you can collect about your customers and their preferences, the better off you'll be. With that in mind, the fact that the Facebook CAPI allows you to accurately track conversions even in the presence of privacy-focused limitations is an enormous boon. The CAPI also gives you a big-picture vision of the customer journey, allowing you to track each user from beginning to end in order to develop a better understanding of them.
Facebook's Conversions API and Facebook Pixel are very closely integrated with one another, so much so that they're occasionally mistaken for being the same tool. While it's true that you need to have a Facebook Pixel on your page to leverage Facebook's CAPI, the two tools differ from one another in a few key ways. First, Facebook Pixel identifies Facebook users that visit your page while logged in — CAPI marks each visitor with their own unique, anonymized ID.
Facebook Pixel also collects and reports data back to Facebook parent company Meta using browser-side tracking, while the CAPI reports data directly to you via server-side tracking.
Caption: Varos allows you to filter and track a wide range of advertising and behavioral data, making it a perfect companion to Facebook's CAPI.