Why aren’t event totals matching up between Events Manager, Custom conversions let you create rules for events or URLs so that you can better track and optimize for specific actions with Facebook ads. More mapped to those events, and Ads Manager? There’s a good reason…
If you dig into your event data, you are likely to notice that the totals for standard and Conversion events tracked by the pixel, app SDK, or API that are outside of standard events. These tend to be created to fit the publisher's needs when a pre-defined standard event will not. More in Data Sources of Events Manager are higher than custom A conversion is counted whenever a website visitor performs an action that fires a standard event, custom event, or custom conversion. Examples of conversions include purchases, leads, content views, add to cart, and registrations. More mapped to those events. The event totals will almost always be higher.
Why? And does this impact Ads Manager Reporting?
Meta has some great documentation on this. Event totals in Events Manager are before PROCESSING and DEDUPLICATION.
When you hear deduplication, you are probably thinking about deduplicating browser and API events. This is part of it. But Meta also deduplicates events that happen by the same person multiple times during a short period.
This deduplication may not be particularly relevant for purchases or leads (unless someone reloads the confirmation page), but it will come up often for lighter-touch events like searches, add-to-cart, view content, and more.
This deduplication hasn’t happened yet when looking at event totals in Events Manager. But if you create a custom conversion mapped to that event, the totals you see here are after deduplication. So this number will almost always be less.
In case you’re wondering, this is ALSO one reason why numbers in Ads Manager reporting are lower.
Of course, event reporting that shows up here will only be what’s attributed to your ads. But even if ALL of your events should come from your ads, Ads Manager reporting may not match up to the raw totals in Events Manager. That’s because, unlike the totals in Events Manager, the events reported in Ads Manager are deduplicated.
This was a bit of a mystery in my community, and it was fun to isolate the explanation.