Low FBP cookie match rate

Hi there!

I’m observing a pretty low FBP cookie match rate when looking into event deduplication - 49%. I’m seeing this only for some events (mostly purchase), whereas, for example, the match rate for add to cart is much higher at 92%.

The FBP is being picked up automatically from cookies in the incoming request. I’m wondering if adding the FBP cookie in the GTM CS, in the event settings, could help with achieving higher match rates.

Have you ever faced a similar issue?


This problem can be on events that are triggered on landing pages (so for ecommerce this is page view and view content events).
This happens when FB js hasn’t loaded yet, but the server tags have already triggered and if you have the option set in the server tag ‘set fbp’ - this will cause different fbp between web and server.
But this should not happen on further events if everything is configured correctly.
I would recommend checking and making sure there is no tag or script that overwrites the _fbp cookie for some reason.

But also note that FB events are very often glitchy and can display incorrect information, so if you are sure that everything is working correctly, wait 1-2 update cycles (data is updated about once every ~48 hours) and see if the problem disappeared by itself at the next update - it happens very often.